Dissertations / Theses: 'Wave run-up'

1

Roux, Abraham Pierre. "A re-assessment of wave run up formulae." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96562.

Full text

Abstract:

Thesis (MEng)--Stellenbosch University, 2015.
ENGLISH ABSTRACT: Over the last few decades, wave run up prediction has gained the interest of numerous researchers and every newly-published paper has aimed to predict wave run up with greater accuracy. Wave run up is defined as the vertical elevation reached by a wave's, front water edge as it runs up a beach, measured relative to the still water line. Wave run up is dependent on the incidental wave height, the wave period, the beach slope and the wave steepness. The majority of publications incorporate all of these factors, but some do not, which has led to numerous debates. The goal of this study is to do a re-assessment of previously published wave run up formulae, to obtain a more informed understanding about wave run up and the available predictive empirical formulae. The study also seeks to evaluate the Mather, Stretch & Garland (2011) formula. The method for undertaking this objective comprised a physical model test series with 10 regular wave conditions on a constant slope, being 1/24, performed with an impermeable floor. Also, a beach study in the field was done on Long Beach, Noordhoek, where run up measurements were taken for 30 minute intervals, resulting in five test conditions. A numerical model was employed in conjunction with the beach study to determine the local offshore wave parameters transformed from a deep water wave rider. This information was used to correlate the run up measurements with known wave parameters. Firstly, the physical model assessment was performed to provide a proper foundation for run up understanding. Plotting empirical normalised run up values (R2/H0 ) versus the Iribarren number for different formulae, a grouping was achieved with upper and lower boundaries. The physical model results plotted on the lower end of this grouping, resulted in prediction differences of more than 10%. These differences may have been caused by the unevenness of the physical model slope or the fact that only one slope had been tested. Despite this, the results fell within a band of wave run up formulae located on the lower end of this grouping. An assessment of the beach measurements in the field gave a better correlation than the physical model results when compared to normalised predicted wave run up formulae. These measurements also plotted on the lower end of the grouping, resulting in prediction differences of less than 10% for some empirical formulae. When comparing these empirical predictions to one another, the results demonstrate that the formulae comparing best with the beach measurements were Holman (1986) and Stockdon, Holman, Howd, & Sallenger Jr. (2006). Extreme over predictions were found by Mase & Iwagaki (1984), Hedges & Mase (2004) and Douglass (1992). Nielsen & Hanslow (1991) only compared best with the beach measurements and De la Pena, Sanchez Gonzalez, Diaz-Sanchez, & Martin Huescar (2012) only compared best to the physical model results. This study supports the formula proposed by Mather, Stretch, & Garland (2011). Applying their formula to the measured results presented a C constant of 3.3 for the physical model and 8.6 for the beach results. Both values are within the range prescribed by the authors. Further reasearch minimized the array of possible „C‟ values by correlating this coefficient to Iribarren numbers. „C‟ values between 3.0~5.0 is prescribed for low Iribarren conditions (0.25-0.4) and values between 7.0~10 for higher Iribarren conditions are 0.75-0.8. However, this formula is still open for operator erros whereby the „C‟ value has a big influence in the final result. The best formulae to use, from results within this thesis, is proposed by Holman (1986) and Stockdon et.al (2006). These formulae are not open to operator erros and uses the significant wave height, deep water wave length and the beach face slope to calculate the wave run up.
AFRIKAANSE OPSOMMING: Gedurende die afgelope paar dekades, het golf-oploop voorspellings die aandag van talle navorsers gelok en elke nuwe geskrewe voorlegging het gepoog om meer akkurate golf-oploop voorspellings te verwesenlik. golf-oploop kan definieer word as die vertikale elevasie bereik deur 'n golf se voorwaterkant soos dit op die strand uitrol, gemeet relatief vanaf die stilwaterlyn. golf-oploop is afhanklik van die invals-golfhoogte, die golfperiode, die strandhelling en die golfsteilheid. Die oorgrote mederheid publikasies uit die literaturr inkorporeer al hierdie faktore, maar sommige nie, wat groot debatvoering tot gevolg het. Die doel met hierdie studie is om vorige gepubliseerde golf- oploop formules te re-evalueer, om 'n meer ingeligte begrip van golf- oploop en beskikbare voorspellende formules te verkry. Die studie poog terselfdertyd ook om golf-opvolg tendense, uniek aan Suid Afrikaanse strande te evalueer deur die huidige formule wat tans hier gebruik word, te assesseer. Om hierdie doelwit te bereik, is gebruik gemaak van 'n fisiese model toets reeks bestaande uit 10 reëlmatige golfstoestande op 'n konstante ondeurlaatbaare strandhelling van 1/24. 'n Veldstudie was ook uitgevoer op Langstrand, Noordhoek, waar golf-oploopmetings met 30 minute tussenposes uitgevoer is, vir vyf toets-toestande. Tesame met die veldstudie, is 'n numeriese model aangewend om die gemete diepsee data nader ann die strand wat bestudeer is te transformeer. Hierdie inligting is benodig om 'n verband tussen tussen oploop-metings en bekende golf parameters te bepaal. Eerstens is die fisiese model assessering uitgevoer om 'n behoorlike basis vir die begrip van golfoploop in die veld te verkry. Deur die emperiese, genormaliseerde oploop waardes (R₂/H₀) vir verkeie formules teenoor die Iribarren getal te plot, is 'n groepering met hoër en laer grense gevind. Daar is gevind dat die fisiese modelwaardes op die laer grens plot, en het verskille met die emperiese waardes van meer as 10% getoon. Hierdie verskille is moontlik veroorsaak as gevolg van 'n oneweredige fisiese model strandhelling of deur die feit dat slegs een helling getoets is. Ten spyte hiervan, het die model oploop waardes binne die bestek van golf- oploop formules geval. Assessering van die veldmetings het 'n beter korrelasie as die fisiese modelresultate getoon, tydens vergelykings met genormaliseerde golf-oploop formules van die emperiese formules. Die oploop waardes van hierdie metings het ook geplot aan die laer grens van die groepering, met verskille van minder as 10% vir die meeste gevalle van die emperiese formules. Wanneer hierdie emperiese voorspellings vergelyk word, is gevind dat die formules wat die beste ooreenstem met die fisiese model, die van Holman (1986) en Stockdon, Howd, & Sallenger Jr. (2006) is. Die emperiese formules van Mase & Iwagake (1984), Hedges & Mase (2004) en Douglas (1992) het die golf-oploop oorvoorspel. Nielsen & Hanslow (1991) het slegs die beste met die strandmetings vergelyk, terwyl De la Pena, Sanchez Gonzalez, Diaz-Sanchez & Martin Huescar (2012) slegs die beste vergelyk het met die fisiese-model resultaat. Hierdie studie ondersteun die formule voorgestel deur Mather, Stretch, & Garland (2011). Deur hul formules op die gemete bevindings toe te pas, is 'n C konstante van 3.3 vir die fisiese model resultate, en 8.0 vir die stranduitlslae bepaal. Beide waardes lê binne die grense wat deur die outeurs voorgestel is. Verdere navorsing het getoon dat moontlike waardes vir die „C‟ konstante tussen 3.0 en 5.0 moet wees vir Iribarren waardes van tussen 0.25 en 0.4. Vir hoër Iribarren waardes, 0.75-0.8, moet die „C‟ kosntante tussen 7.0 en 10 wees; dog is die formule steeds oop vir operateur foute. Die hoofbevindinge van die tesis is gevind dat die beste golf-oploop formules, om tans te gebruik, die van Holman (1986) en Stockdon et.al (2006) is. Hierdie formules kan glad nie beinvloed word deur operateurs foute nie en maak gebruik van die invals golfhoogte, die golfperiode en die strandhelling om die golf-oploop te bepaal.

APA, Harvard, Vancouver, ISO, and other styles

2

Morris-Thomas, Michael. "An investigation into wave run-up on vertical surface piercing cylinders in monochromatic waves." University of Western Australia. School of Oil and Gas Engineering, 2003. http://theses.library.uwa.edu.au/adt-WU2004.0010.

Full text

Abstract:

[Formulae and special characters can only be approximated here. Please see the pdf version of the abstract for an accurate reproduction.] Wave run-up is the vertical uprush of water when an incident wave impinges on a free- surface penetrating body. For large volume offshore structures the wave run-up on the weather side of the supporting columns is particularly important for air-gap design and ultimately the avoidance of pressure impulse loads on the underside of the deck structure. This investigation focuses on the limitations of conventional wave diffraction theory, where the free-surface boundary condition is treated by a Stokes expansion, in predicting the harmonic components of the wave run-up, and the presentation of a simplified procedure for the prediction of wave run-up. The wave run-up is studied on fixed vertical cylinders in plane progressive waves. These progressive waves are of a form suitable for description by Stokes' wave theory whereby the typical energy content of a wave train consists of one fundamental harmonic and corresponding phase locked Fourier components. The choice of monochromatic waves is indicative of ocean environments for large volume structures in the diffraction regime where the assumption of potential flow theory is applicable, or more formally A/a < Ο(1) (A and a being the wave amplitude and cylinder radius respectively). One of the unique aspects of this work is the investigation of column geometry effects - in terms of square cylinders with rounded edges - on the wave run-up. The rounded edges of each cylinder are described by the dimensionless parameter rc/a which denotes the ratio of edge corner radius to half-width of a typical column with longitudinal axis perpendicular to the quiescent free-surface. An experimental campaign was undertaken where the wave run-up on a fixed column in plane progressive waves was measured with wire probes located close to the cylinder. Based on an appropriate dimensional analysis, the wave environment was represented by a parametric variation of the scattering parameter ka and wave steepness kA (where k denotes the wave number). The effect of column geometry was investigated by varying the edge corner radius ratio within the domain 0 <=rc/a <= 1, where the upper and lower bounds correspond to a circular and square shaped cylinder respectively. The water depth is assumed infinite so that the wave run-up caused purely by wave-structure interaction is examined without the additional influence of a non-decaying horizontal fluid velocity and finite depth effects on wave dispersion. The zero-, first-, second- and third-harmonics of the wave run-up are examined to determine the importance of each with regard to local wave diffraction and incident wave non-linearities. The modulus and phase of these harmonics are compared to corresponding theoretical predictions from conventional diffraction theory to second-order in wave steepness. As a result, a basis is formed for the applicability of a Stokes expansion to the free-surface boundary condition of the diffraction problem, and its limitations in terms of local wave scattering and incident wave non-linearities. An analytical approach is pursued and solved in the long wavelength regime for the interaction of a plane progressive wave with a circular cylinder in an ideal fluid. The classical Stokesian assumption of infinitesimal wave amplitude is invoked to treat the free-surface boundary condition along with an unconventional requirement that the cylinder width is assumed much smaller than the incident wavelength. This additional assumption is justified because critical wavelengths for wave run-up on a fixed cylinder are typically much larger in magnitude than the cylinder's width. In the solution, two coupled perturbation schemes, incorporating a classical Stokes expansion and cylinder slenderness expansion, are invoked and the boundary value problem solved to third-order. The formulation of the diffraction problem in this manner allows for third-harmonic diffraction effects and higher-order effects operating at the first-harmonic to be found. In general, the complete wave run-up is not well accounted for by a second-order Stokes expansion of the free-surface boundary condition and wave elevation. This is however, dependent upon the coupling of ka and kA. In particular, whilst the modulus and phase of the second-harmonic are moderately predicted, the mean set-up is not well predicted by a second-order Stokes expansion scheme. This is thought to be caused by higher than second-order non-linear effects since experimental evidence has revealed higher-order diffraction effects operating at the first-harmonic in waves of moderate to large steepness when k < < 1. These higher-order effects, operating at the first-harmonic, can be partially accounted for by the proposed long wavelength formulation. For small ka and large kA, subsequent comparisons with measured results do indeed provide a better agreement than the classical linear diffraction solution of Havelock (1940). To account for the complete wave run-up, a unique approach has been adopted where a correction is applied to a first-harmonic analytical solution. The remaining non-linear portion is accounted for by two methods. The first method is based on regression analysis in terms of ka and kA and provides an additive correction to the first-harmonic solution. The second method involves an amplification correction of the first-harmonic. This utilises Bernoulli's equation applied at the mean free-surface position where the constant of proportionality is empirically determined and is inversely proportional to ka. The experimental and numerical results suggest that the wave run-up increases as rc/a--› 0, however this is most significant for short waves and long waves of large steepness. Of the harmonic components, experimental evidence suggests that the effect of a variation in rc/a on the wave run-up is particularly significant for the first-harmonic only. Furthermore, the corner radius effect on the first-harmonic wave run-up is well predicted by numerical calculations using the boundary element method. Given this, the proposed simplified wave run-up model includes an additional geometry correction which accounts for rc/a to first-order in local wave diffraction. From a practical view point, it is the simplified model that is most useful for platform designers to predict the wave run-up on a surface piercing column. It is computationally inexpensive and the comparison of this model with measured results has proved more promising than previously proposed schemes.

APA, Harvard, Vancouver, ISO, and other styles

3

Shiach, Jonathan Ben. "Numerical modelling of wave run-up and overtopping using depth integrated equations." Thesis, Manchester Metropolitan University, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.486867.

Full text

Abstract:

Wave run-up and overtopping of coastal structures have been extensively studied over the last 30 years to provide guidance for the construction of sea defences. Numerical models based on fluid flow equations can provide a useful aid in the design of these coastal defences. Computers have now advanced sufficiently to enable programs written to solve the flow equations to run on hardware that is readily available (e.g., desktop or laptop computers), thus giving engineers the ability to conduct multiple runs of an experiment, reconfigure the bathymetry, change the wave conditions and collect data from anywhere in the solution domain. An existing numerical model, AMAZON, based on the non-linear Shallow \Vater Equations (S\VE) was used to give wave height and overtopping discharges for a series of violent overtopping experiments. A second-order accurate highresolution finite-volume method was used to solve the SWE. The source terms that model the bed topography were treated using the Surface Gradient Method (SGM). The numerical model gave overtopping predictions to within 20% of the experimental overtopping discharges for cases where the wave ~onditions at the sea wall were not severely impacting. However, wave height comparisons showed that the SWE could not model wave propagation in intermediate depth water. The Boussinesq class of equations was chosen to extend the numerical modelling of wave propagation, run-up and overtopping into intermediate depth water. A hybrid finite-volumejfinite-difference solver was used to solve two different extended Boussinesq formulations, one of which was chosen to model a range of run-up and overtopping experiments. It was found'that the numerical model was able to model wave propagation where the typical depth to wavelength ratio was less than 0.35 for both regular and irregular waves. However, the numerical model was not able to accurately model breaking waves. Comparisons between overtopping discharges from the physical experiments and the numerical model showed that, in the majority of cases, the numerical model was able to provide predictions to within an absolute relative error of 3. It was found that as the gradient of the seawall increa'3ed, so did the accuracy of the numerical overtopping predictions.

APA, Harvard, Vancouver, ISO, and other styles

4

Orszaghova, Jana. "Solitary waves and wave groups at the shore." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:5b168bdc-4956-4152-a303-b23a6067bf42.

Full text

Abstract:

A significant proportion of the world's population and physical assets are located in low lying coastal zones. Accurate prediction of wave induced run-up and overtopping of sea defences are important in defining the extent and severity of wave action, and in assessing risk to people and property from severe storms and tsunamis. This thesis describes a one-dimensional numerical model based on the Boussinesq equations of Madsen and Sorensen (1992) and the non-linear shallow water equations. The model is suitable for simulating propagation of weakly non-linear and weakly dispersive waves from intermediate to zero depth, such that any inundation and/or overtopping caused by the incoming waves is also calculated as part of the simulation. Wave breaking is approximated by locally switching to the non-linear shallow water equations, which can model broken waves as bores. A piston paddle wavemaker is incorporated into the model for complete reproduction of laboratory experiments. A domain mapping technique is used in the vicinity of the paddle to transform a time-varying domain into a fixed domain, so that the governing equations can be more readily solved. First, various aspects of the numerical model are verified against known analytical and newly derived semi-analytical solutions. The complete model is then validated with laboratory measurements of run-up and overtopping involving solitary waves. NewWave focused wave groups, which give the expected shape of extreme wave events in a linear random sea, are used for further validation. Simulations of experiments of wave group run-up on a plane beach yield very good agreement with the measured run-up distances and free surface time series. Wave-by-wave overtopping induced by focused wave groups is also successfully simulated with the model, with satisfactory agreement between the experimental and the predicted overtopping volumes. Repeated simulations, now driven by second order paddle displacement signals, give insight into second order error waves spuriously generated by using paddle signals derived from linear theory. Separation of harmonics reveals that the long error wave is significantly affecting the wave group shape and leading to enhanced runu-up distances and overtopping volumes. An extensive parameter study is carried out using the numerical model investigating the influence on wave group run-up of linear wave amplitude at focus, linear focus location, and wave group phase at focus. For a given amplitude, both the phase and the focus location significantly affect the wave group run-up. It is also found that the peak optimised run-up increases with the wave amplitude, but wave breaking becomes an inhibiting factor for larger waves. This methodology is proposed for extreme storm wave induced run-up analysis.

APA, Harvard, Vancouver, ISO, and other styles

5

Chapman, Neil. "Modelling the dynamic interaction between hydrology, slope stability and wave run-up processes in the soft-sea cliffs at Covehithe, Suffolk, UK." Thesis, Birkbeck (University of London), 2014. http://bbktheses.da.ulcc.ac.uk/98/.

Full text

Abstract:

Soft-rock coastal cliff retreat progresses by an intermittent and discontinuous series of slope mass movements, generally accepted to be concentrated during phases of strong wave attack or heavy rain. One of the fundamental limitations to improving understanding of these processes is a lack of accurate quantitative data on the hydrological and geotechnical behaviour of the cliff slope. In this study, high-resolution terrestrial surveys of coastal change over a fifteen year period have been analysed and combined with hydrological and geotechnical simulations of cliff behaviour under rainfall stress. The input parameters for the simulations have been established from site survey, cross-checked with data from a range of published literature. The numerical model has been applied to typical hydrological, climatic and geotechnical conditions at Covehithe, Suffolk. In addition, analyses of water levels and beach elevations have subsequently been included using archive observation data, to further investigate the mechanisms governing the nature of change at the study site. Key findings include: (a.) high-resolution modelling of rainfall-infiltration processes combined with slope stability analysis provides a unique insight into the complex interaction between slope morphology and dynamic hydrology in soft sea cliffs. (b.) detailed analysis of daily factors of safety related to specific daily rainfalls is significant in reproducing failure conditions at the study site, and elucidates the complex interaction between cliff stratigraphy, cliff hydrology and rainfall. (c.) The results of the water level and beach elevation analyses show that marine processes are significant to the generation of cliff instability, consistent with the field observations and with the Sunamura (1983) model. These findings suggest that the instability of soft sea-cliffs results from complex and interacting controls that require an approach utilising a fully integrated transient hydrology and slope stability modelling. These results have significant implications for current coastal management practice.

APA, Harvard, Vancouver, ISO, and other styles

6

Wilson, Jessica. "The Efficacy and Design of Coastal Protection Using Large Woody Debris." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/41573.

Full text

Abstract:

Those who frequent the coastline may be accustomed to seeing driftwood washed onshore, some of it having seemingly found a home there for many years, others having been freshly deposited during the last set of storms; However, if a passerby were to take a closer look at the driftwood on the coastline, they may notice that some of these logs – also known as Large Woody Debris (LWD) – are anchored in place, a practice which is generally used for the purpose of stabilizing the shoreline or reducing wave-induced flooding. Records of existing anchored LWD project sites date back to 1997 and anecdotal evidence suggests that the technique has been used since the mid-1900’s in coastal British Columbia (BC), Canada, and Washington State, USA. Now, with an increased demand for natural and nature-based solutions, the technique is again gaining popularity. Despite this, the design of anchored LWD has largely been based on anecdotal observations and experience, as well as a continuity of design practices from the river engineering field. To date, there is no known peer-reviewed literature on the design or efficacy of LWD protection systems in a coastal environment. In 2019, the “Efficacy and Design of Coastal Protection using Large Woody Debris” research project was initiated to determine if LWD are effective at stabilizing the shoreline under wave action, if they are effective at reducing wave run-up, and if they are durable enough to meet engineering requirements for shore protection. In addition, the project aimed to determine the optimum configuration of LWD for design purposes. To meet these objectives, this study included the following work: (1) field studies of existing LWD installations, (2) experimental modeling of beach morphology with and without LWD structures, (3) experimental modeling of wave run-up with and without LWD structures, and (4) development of preliminary design guidance. The first phase of the project included field investigations at 15 existing anchored LWD sites in coastal BC and Washington State. Site characteristics, design techniques, and durability indicators were examined and correlated to a new design life parameter: ‘Effective Life’. Six primary installation techniques were observed: Single, Multiple, Benched, Stacked, Matrix, and Groyne. Observed durability and/or performance issues included: missing LWD, erosion, arson, wood decay, and anchor corrosion/damage. The Effective Life of anchored LWD was found to be strongly correlated to the tidal range and the upper beach slope for all installation types, and the LWD placement elevation relative to the beach crest elevation for single, shore-parallel structures. The many noted durability issues and ineffectiveness as mitigating erosion indicates that existing design methods for anchored LWD have not generally been effective at providing coastal protection and meeting engineering design life requirements. A comprehensive set of over 60 experimental tests were completed as part of the overall research program. Thirty-two (32) tests were analyzed as part of this study relating to the morphological response of a gravel beach with and without various LWD configurations. The tests were conducted within a wave flume at the National Research Council’s Ocean, Coastal and River Engineering Research Centre (NRC-OCRE), at a large scale (5:1) based on site characteristics and LWD design characteristics made during the previous field investigations. Tests were also conducted to assess experiment repeatability, sensitivity to test duration, sensitivity to wave height, wave period, and relative water level, influence of regular waves, and influence of log roughness. The position of the most seaward LWD (whether considering distance or elevation) was found to be strongly linked to morphological response. A theoretical relationship was developed between LWD elevation and sediment volume change. Configurations which included LWD placement below the still water level, such as the Benched configuration, were found to be most effective at stabilizing the beach profile. As part of the experimental modeling program, 24 tests were also conducted for the purpose of estimating the effect of LWD design configuration on wave run-up. In total, six different beach and LWD configurations were tested under a base set of four regular wave conditions. The study findings indicated that anchored LWD may increase wave run-up relative to a gravel beach with no structures. In particular, configurations with more logs tended to result in higher wave run-up. However, additional research is needed on the effect of LWD on wave run-up to confirm and expand these findings. There are a number of potential engineering, ecological, social, and economic benefits associated with anchored LWD installations if designed, installed, and monitored appropriately for the site conditions and user needs. To realize these potential benefits, significant additional research is needed on the topic. One of the most significant barriers to usage is a lack of information on how to effectively anchor LWD structures. However, this research project provides a baseline for future comprehensive studies on the effect and design of coastal protection using LWD. The project provides preliminary design considerations for the usage of LWD as coastal protection and contributes to the growing body of literature on nature-based solutions.

APA, Harvard, Vancouver, ISO, and other styles

7

Röhner, Michael. "Schwallwellen infolge der Bewegung einer Begrenzungsfläche." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-77100.

Full text

Abstract:

Restlöcher ausgekohlter Braunkohlentagebaue werden aus landeskulturellen und ökonomischen Gründen wasserwirtschaftlich als Speicher, Hochwasserrückhaltebecken, Klärteiche, Wassergewinnungsanlagen sowie zur Naherholung genutzt. Diese Restlöcher werden zum großen Teil von aus geschüttetem Abraum bestehenden Böschungen umschlossen. Bei Wasserspiegelschwankungen neigen diese unbefestigten Böschungen zum Rutschen. Als Folge dieser Böschungsrutschungen bilden sich auf der Wasseroberfläche Wellen, die eine beachtliche Größe erreichen können. Diese Schwallwellen übertreffen in ihren Ausmaßen die Windwellen in den Tagebaurestlöchern um ein Vielfaches. Um diese Erscheinungen vorausberechnen zu können, wurden im Hubert-Engels-Laboratorium der Sektion Wasserwesen Untersuchungen durchgeführt. Die Entwicklung einer allgemeingültigen Berechnungsmethode für die Schwallwelle bei der Bewegung eines Teiles der das Wasserbecken begrenzenden Böschung verlangt die Einführung erfassbarer Parameter wie der Breite der rutschenden Böschung, den zeitlichen Verlauf der Wasserverdrängung sowie Tiefen- und Lageverhältnisse des Beckens. Die dafür notwendigen Kennzahlen können nur näherungsweise bestimmt werden, so dass einfache Beckengeometrien, ein über die Rutschzeit gleich bleibender Verlauf der Wasserverdrängung und Erhaltung der Böschungskante einem Berechnungsverfahren zugrunde gelegt werden müssen. Für die Berechnung des Füllschwalles auf das ruhende Wasser sind einige Verfahren bekannt geworden, die auf eine gemeinsame Gleichung für die Berechnung der Schwallhöhe zurückzuführen sind. Für die ebene Ausbreitung des Füllschwalles über Ruhewasser ergeben sieh zwei prinzipielle Abflussmöglichkeiten: Auflösung in Wellen oder brandender Schwallkopf. Diese beiden Möglichkeiten sowie der Übergangsbereich werden durch FROUDE-zahlen festgelegt. Der Wellenkopf von Füllschwallwellen wird durch eine Einzelwelle gebildet. Die Rutschung einer Böschung wurde durch die gleichzeitige Horizontal- und Vertikalbewegung einer Platte nachgebildet. Die Bewegung der Platte, die entstehenden Wellen und die Kräfte auf Auflaufböschung wurden durch einen Oszillografen aufgezeichnet. Die Auswertung der Versuche ergab eine Übereinstimmung zwischen Messergebnissen und den Berechnungen nach den Gesetzen des Füllschwalls. Die sekundlich verdrängte Wassermenge pro Breiteneinheit und die Ruhewassertiefe bestimmen die entstehenden Schwallwellen. Ein Einfluss der vertikalen Bewegungskomponente ist im untersuchten Bereich nicht nachweisbar. Die dynamischen Kräfte auf die Abschlussböschung können durch den Impuls der Einzelwelle dargestellt werden. Die räumliche Ausbreitung der Schwallwellen wurde in einem Modell untersucht. Dabei wurde festgestellt, dass die größten Wellenhöhen in der Richtung der Bewegung der Platte auftreten, während die Wellenhöhen in seitlichen Ausbreitungsrichtungen kleiner sind. Berechnungsansätze für die maximale Wellenhöhe der front wurden ermittelt. Als Ergebnis wurde ein Berechnungsverfahren entwickelt, welches ausgehend von den Parametern dar Rutschung, die Eigenschaften der Schwallwellen einschließlich der durch sie hervorgerufenen Belastungen auf der Auflaufböschung ermöglicht. Mit diesem Berechnungsverfahren ist es möglich, Böschungen wirtschaftlich zu gestalten und schädliche Rückwirkungen auf das Staubecken durch Schwallwellen zu vermeiden. Bisher notwendige Kosten für eine sehr flache Gestaltung der Böschung können entfallen. Gleichzeitig bleibt ein größerer nutzbarer Stauraum erhalten. Die Digitalisierung der vorliegenden Arbeit durch die Sächsische Landesbibliothek - Staats- und Universitätsbibliothek Dresden (SLUB) wurde durch die Gesellschaft der Förderer des Hubert-Engels-Institutes für Wasserbau und Technische Hydromechanik an der Technischen Universität Dresden e.V. unterstützt.

APA, Harvard, Vancouver, ISO, and other styles

8

Silva, Guilherme Vieira da. "Cota de inundação e recorrência para a enseada do Itapocorói e praia de Morro dos Conventos, Santa Catarina." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2012. http://hdl.handle.net/10183/56330.

Full text

Abstract:

Este trabalho apresenta o cálculo da cota de inundação para a Enseada do Itapocorói e para a praia de Morro dos Conventos, litoral do Estado de Santa Catarina. Para atingir os objetivos desse trabalho, a cota de inundação foi calculada através da soma das marés meteorológica e astronômica e do wave run-up. Foi utilizada uma base de 60 anos (horária) de dados de marés e ondas, além de dados de batimetria e topografia das praias. Com o intuito de se obter dados mais realistas do wave run-up, os parâmetros ondulatórios da base de dados foram transferidos de águas profundas para próximo da costa com a utilização do modelo SWAN (Simulating Waves Nearshore). A Enseada do Itapocorói foi dividida em quatro setores (exposto, semiexposto, semiprotegido e protegido) em função dos diferentes graus de exposição à ação de ondas, sendo as equações calibradas para cada setor. A partir dos resultados para Enseada do Itapocorói, notou-se que quanto mais exposta a praia, melhor as equações existentes representavam o wave run-up, assim, para a praia de Morro dos Conventos foi utilizada a equação mais aceita na literatura sem calibração. A cota de inundação instantânea foi calculada para cada hora da série de 60 anos somando-se o wave run-up às marés astronômicas e meteorológicas. Sobre a série de cota de inundação instantânea, para ambas as áreas, foi calculada a cota atingida durante 50% do tempo e por eventos extremos com recorrência de 50, 100 e 200 anos. A estas foi adicionada a previsão de elevação do nível do mar de longo prazo para o mesmo período. A cota atingida durante 50% do tempo na Enseada do Itapocorói foi de 1,35 m no setor exposto, enquanto nos setores semiexposto, semiprotegido e protegido foi de 1 m, 0,9 m e 0,7 m respectivamente. Também, o setor exposto foi o que apresentou as maiores cotas atingidas, sendo 3,45 m, 3,85 m e 4,45 m com tempo de recorrência de 50,100 e 200 anos respectivamente. No setor semiexposto, os valores calculados foram de 2,85 m (50 anos), 3,25 m (100 anos) e 3,9 m (200 anos). No setor semiprotegido, as cotas com tempo de recorrência de 50, 100 e 200 anos foram de 2,65 m, 3,05 m, 3,75 m respectivamente. Já o setor protegido apresentou as menores cotas entre os setores, 2,4 m, 2,85 m e 3,5 m para 50, 100 e 200 anos de tempo de recorrência. Considerando a extensão da área costeira que possui um levantamento de topografia do terreno, 2,4 % da área é inundada durante 50% do tempo, subindo para 26%, 29% e 33% nos casos de recorrência com 50, 100 e 200 anos. A cota atingida na praia de Morro dos Conventos durante 50% do tempo é de 1,1 m, já as cotas calculadas para os tempos de recorrência de 50, 100 e 200 anos foram de 4,2 m, 4,6 m e 5,35 m respectivamente. E, da mesma forma, a área costeira com levantamento topográfico teve 15% de superfície é inundada em 50% do tempo, passando para 85%, 91% e 96% da área total analisada com 50, 100 e 200 anos de tempo de recorrência. A metodologia proposta neste trabalho contribui para o planejamento de zonas costeiras, à medida que indica áreas afetadas por inundação aos eventos extremos. A apresentação de cartas contendo esse tipo de informação em ambiente de SIG facilita a tomada de decisão e o entendimento da área por determinado evento extremo.
The goal of this study is to determine the inundation levels at Ensenada do Itapocorói and Morro dos Conventos beaches, located in Santa Catarina State. This was accomplished through the calculation of the inundation level as the sum of astronomical and meteorological tides and wave run-up. The database for this study included -60 years of hourly waves and tides, bathymetric and topographic data. The instantaneous sea level has been defined for each hour of the data series through the summation of astronomical and meteorological tides. To determine more realistic wave run-up data, the wave parameters have been propagated to shallower water using the SWAN (Simulating WAves Nearshore) model. Published equations were used and results were compared with measured data at a headland bay beach (Enseada do Itapocorói); furthermore, the equations have been calibrated for four sectors of the bay (exposed, semi-exposed, semi-protected and protected). Morro dos Conventos is an exposed beach, comparable to those for which the equations have been developed, so the raw, un-calibrated equations were applied for this site. The inundation level was calculated for each hour of the 60 year-long series by summing the run-up values to obtain the instantaneous level. Over the series of inundation levels, the area inundated during 50% of the time, and the return period for this inundation, have been calculated for 50, 100 and 200 years. The sea-level rise prediction for each calculated period has also been incorporated in order estimate the area likely to be inundated by future events. For Enseada do Itapocorói, the inundation level reached 50% of the time was 1,35 m in the exposed sector, 1 m in the semi-exposed sector, 0,9 m in the semi-protected sector and 0,7 in the protected sector. The exposed sector demonstrated the highest values of inundation, 3,45, 3,85 and 4,5 m for 50, 100 and 200 years of return period respectively. At the semi-exposed sector, the values calculated were 2,85 (50 years), 3,25 (100 years) and 3,9 (200 years) m. At semi-protected sector, inundation levels for the 50-, 100- and 200-year return period intervals were 2,65, 3,05 and 3,75 m, respectively. At the protected sector the lowest levels were reached: 2,4, 2,85 and 3,5 m for 50-, 100- and 200-year return period intervals. 2,4% of the total area for which topographic data is available would be inundated during 50% of the time, increasing to 26%, 29% and 33% for 50-, 100- and 200-year return periods. At Morro dos Conventos, the level of inundation reaches 1,1 m 50% of the time;, for 50,100 and 200 years the level rises to 4,2, 4,6 and 5,36 m respectively. Approximately 15% of the area for which topographic data is available would be area is inundated during 50% of the time, 85% with a 50 year return period, 91% with a 100-year period and 96% with a 200 year period.

APA, Harvard, Vancouver, ISO, and other styles

9

Williams, Steven Mark. "The run-up and overtopping of shallow water waves." Thesis, University of Bristol, 2003. http://hdl.handle.net/1983/1737edc5-15c3-4fc6-b5eb-cc598df55ca2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Guibourg, Sandrine. "MModélisations numérique et expérimentale des houles bidimensionnelles en zone cotière." Université Joseph Fourier (Grenoble), 1994. http://www.theses.fr/1994GRE10160.

Full text

Abstract:

Une analyse theorique detaillee des equations de boussinesq et de serre a ete realisee. Les domaines de validite de chaque equation ont ete determines theoriquement. Ces equations d'ondes longues sont discretisees selon un schema aux differences finies pour des ondes de surface libre sur fond plat et fond variable. Par le biais d'une comparaison numerique avec des essais experimentaux d'ondes longues sur fond plat, les modeles numeriques ont ete etendus a la description des ondes courtes. Un terme dispersif correctif a ete introduit pour ameliorer les capacites dispersives des modeles. Des essais numeriques de propagation d'ondes longues sur un talus ont egalement ete compares aux experiences. Une etude de l'interaction d'une houle courte de haute frequence avec une onde solitaire nous a conduit a mesurer le dephasage que subit l'onde courte apres le passage du soliton. Nous nous sommes consacres a la validation experimentale d'une comparaison entre les modeles de boussinesq et de serre sur des plages peu inclinees, ainsi qu'a l'evolution du nombre d'ursell le long de la plage. L'etude experimentale a ensuite ete etendue aux phenomenes de run up, de run down et aux calculs des coefficients de reflexion des plages etudiees. Pour calculer numeriquement les run up, nous avons ameliore le modele de serre par des conditions de trait de cote variable

APA, Harvard, Vancouver, ISO, and other styles

11

Lin, Duo-min Wu Theodore Y. T. Wu Theodore Y. T. "Run-up and nonlinear propagation of oceanic internal waves and their interactions /." Diss., Pasadena, Calif. : California Institute of Technology, 1996. http://resolver.caltech.edu/CaltechETD:etd-12192007-084353.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Zhang, Jin E. Wu Theodore Y. T. Wu Theodore Y. T. "I. Run-up of ocean waves on beaches. : II. Nonlinear waves in a fluid-filled elastic tube /." Diss., Pasadena, Calif. : California Institute of Technology, 1996. http://resolver.caltech.edu/CaltechETD:etd-01072008-105605.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Campos, Maria Manuel Trindade. "Public sector wage gap and fiscal adjustments on the run-up to the euro area." Master's thesis, Instituto Superior de Economia e Gestão, 2011. http://hdl.handle.net/10400.5/4310.

Full text

Abstract:

Mestrado em Econometria Aplicada e Previsão
This study examines the fiscal adjustments that took place on the run-up to the euro area and how were they reflected on the func¬tioning of the public sector labour markets in euro area countries. OECD data are used to identify and characterize episodes of fiscal consolidation in a broad set of countries and within the 1983-2001 time-frame, but focusing, in particular, on those corresponding to the euro area founding Member States and to the 1993-1997 period. To assess developments referring to compensation of employees and how the occurrence of these episodes affected public sector employment and wage growth in countries that in the 1990s were engaged in the fulfilment of the Maastricht criteria, microeconomic data drawn from the European Community Household Panel is used. Such data is also employed to estimate the public-private wage gap, using a novel ap¬proach that allows the estimation of quantile regressions accounting for individual-specific fixed effects. Results suggest that, on the run-up to the euro area, macroeconomic and interest rate conditions made it easier to comply with the Maastricht criteria without requiring partic¬ularly strong primary expenditure cuts. Regarding, more specifically, the expenditure with compensation of employees, there is evidence of a relative moderation in terms of the admission of civil servants, wage growth and the evolution of public-private wage gaps, but it is not striking and was reversed shortly after the assessment of the criteria. This may explain why none of the fiscal adjustments identified in euro area countries in 1993-1997 was successful in persistently reducing public debt ratios.
O presente estudo pretende analisar os ajustamentos orçamentais que ocorreram no período anterior ao início da UEM e de que modo os mesmos se reflectiram no funcionamento dos mercados de trabalho do sector público da área do euro. Com base em dados da OCDE, são identificados e caracterizados episódios de consolidação orçamental num conjunto alargado de países entre 1983 e 2001, mas atenção especial e devotada aos correspondentes aos países fundadores da UEM e ao período de 1993 a 1997. Com o objectivo de estudar a evolução das despesas com pessoal e de que forma a ocorrência destes episódios afectou o crescimento do emprego e dos salários no sector público em países que ao longo da decada de 1990 estavam envolvidos no cumprimento dos critérios de Maastricht, são usados dados microeconómicos do Painel de Agregados Familiares da Comunidade Europeia. Estes dados são igualmente empregues para estimar prémios salariais associados ao sector público, usando uma nova abordagem que permite a estimação de regressões de quantis tendo em conta efeitos fixos específicos aos indivíduos. Os resultados obtidos sugerem que, no período anterior ao início da UEM, as condições macroeconómicas e a evolucção das taxas de juro facilitaram o cumprimento dos critérios de Maastricht sem necessidade de cortes severos na despesa primária. No que respeita, mais concretamente, às despesas com pessoal, existem indícios de uma relativa moderação em termos da admissão de novos funcionários públicos, do crescimento dos salários e da evolução dos prémios salariais, mas a mesma não parece ter sido particularmente forte, verificando-se uma reversão logo após a avaliação do cumprimento dos critérios. Estes factores poderão explicar por que razão nenhum dos ajustamentos orçamentais identificados em países da UEM no período 1993-1997 produziu efeitos duradouros de reduçcão dos rácios da dívida.

APA, Harvard, Vancouver, ISO, and other styles

14

Stefanakis, Themistoklis. "Tsunami amplification phenomena." Phd thesis, École normale supérieure de Cachan - ENS Cachan, 2013. http://tel.archives-ouvertes.fr/tel-00920527.

Full text

Abstract:

This thesis is divided in four parts. In the first one I will present our work on long wave run-up and some resonant amplification phenomena. With the use of numerical simulations for the nonlinear shallow water equations, we show that in the case of monochromatic waves normally incident on a plane beach, resonant run-up amplification occurs when the incoming wavelength is 5.2 times larger the beach length. We also show that this resonant run-up amplification can be observed for several wave profiles such as bichromatic, polychromatic and cnoidal. However, resonant run-up amplification is not restricted to infinitely sloping beaches. We varied the bathymetric profile, and we saw that resonance is present in the case of piecewise linear and real bathymetries. In the second part I will present a new analytical solution to study the propagation of tsunamis from a finite strip source over constant depth using linear shallow-water wave theory. The solution, which is based on separation of variables and a double Fourier transform in space, is exact, easy to implement and allows the study of realistic waveforms such as N-waves. In the third part I will explore the effect of localized bathymetric features on long wave generation. Even when the final displacement is known from seismic analysis, the deforming seafloor includes relief features such as mounts and trenches. We investigate analytically the effect of bathymetry on the surface wave generation, by solving the forced linear shallow water equation. Our model for bathymetry consists of a cylindrical sill on a flat bottom, to help understand the effect of seamounts on tsunami generation. We derive the same solution by applying both the Laplace and the Fourier transforms in time. We find that as the sill height increases, partial wave trapping reduces the wave height in the far field, while amplifying it above the sill. Finally, in the last part I will try to explore whether small islands can protect nearby coasts from tsunamis as it is widely believed by local communities. Recent findings for the 2010 Mentawai Islands tsunami show amplified run-up on coastal areas behind small islands, compared with the run-up on adjacent locations, not influenced by the presence of the islands. We will investigate the conditions for this run-up amplification by numerically solving the nonlinear shallow water equations. Our bathymetric setup consists of a conical island sitting on a flat bed in front of a plane beach and we send normally incident single waves. The experimental setup is governed by five physical parameters. The objective is twofold: Find the maximum run-up amplification with the least number of simulations. Given that our input space is five-dimensional and a normal grid approach would be prohibitively computationally expensive, we present a recently developed active experimental design strategy, based on Gaussian Processes, which significantly reduces the computational cost. After running two hundred simulations, we find that in none of the cases considered the island did offer protection to the coastal area behind it. On the contrary, we have measured run-up amplification on the beach behind it compared to a lateral location on the beach, not directly affected by the presence of the island, which reached a maximum factor of 1.7. Thus, small islands in the vicinity of the mainland will act as amplifiers of long wave severity at the region directly behind them and not as natural barriers as it was commonly believed so far.

APA, Harvard, Vancouver, ISO, and other styles

15

Angeli, Cesare. "Analytical solutions for the run-up of long water waves excited by time-independent and time-dependent forcing." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/21772/.

Full text

Abstract:

Nello studio fisico e matematico dei maremoti, l'interazione con la costa, o problema del run-up rappresenta ancora oggi una grande sfida. Da un lato, si tratta forse del problema di maggiore urgenza, in quanto è proprio all'arrivo alla terra ferma che il maremoto causa le maggiori perdite umane e materiali. Dall'altro lato, la formulazione matematica del problema è particolarmente complessa ed alcune caratteristiche del fenomeno non sono ancora ben comprese. In questa tesi viene proposto un metodo di calcolo della posizione della linea di costa in problemi bidimensionali, che suppone di poter applicare le equazioni della fluidodinamica in approssimazione di shallow water lineare. Se la prima di queste ipotesi è sempre utilizzata in questo contesto, questo non vale per la seconda. In generale il problema è non lineare e prevede condizioni al contorno mobili. Nonostante ciò, si può notare un fatto sorprendente: i problemi ai valori iniziali in formulazione lineare e non lineare producono soluzioni con gli stessi punti stazionari. Spesso l'informazione fondamentale che si vuole ottenere è l'estensione dell'area inondata, ovvero il valore massimo del run-up, che sarà previsto quindi correttamente anche in approssimazione lineare. Sulla base di queste considerazioni, viene presentato un modello capace di prevedere l'inondazione su una spiaggia lineare dovuta ad una qualsiasi deformazione del fondale che sia piccola rispetto alla profondità locale del mare. Questo modello è quindi applicabile nel caso di terremoti e frane sottomarine in prossimità della costa. I risultati delle applicazioni sono in accordo con i principali studi analoghi presenti in letteratura. Per questo, il modello è utilizzato per alcuni casi nuovi, ovvero uno studio della dipendenza del run-up massimo dalla magnitudo, in cui le caratteristiche della faglia sono dedotte da leggi di scala, e un nuovo semplice modello per una frana di forma Gaussiana con parametri variabili nel tempo.

APA, Harvard, Vancouver, ISO, and other styles

16

Goseberg, Nils [Verfasser]. "The run-up of long waves : laboratory-scaled geophysical reproduction and onshore interaction with macro-roughness elements / Nils Goseberg." Hannover : Technische Informationsbibliothek und Universitätsbibliothek Hannover (TIB), 2011. http://d-nb.info/1015446965/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Ricchiuto, Mario. "Contributions to the development of residual discretizations for hyperbolic conservation laws with application to shallow water flows." Habilitation à diriger des recherches, Université Sciences et Technologies - Bordeaux I, 2011. http://tel.archives-ouvertes.fr/tel-00651688.

Full text

Abstract:

In this work we review 12 years of developments in the field of residual based discretizations for hyperbolic problems and their application to the solution of the shallow water equations. Fundamental concepts related to the topic are recalled and he construction of second and higher order schemes for steady problems is presented. The generalization to time dependent problems by means of multi-step implicit time integration, space-time, and genuinely explicit techniques is thoroughly discussed. Finally, the issues of C-property, super consistency, and wetting/drying are analyzed in this framework showing the power of the residual based approach.

APA, Harvard, Vancouver, ISO, and other styles

18

Dawe, Iain Nicholas. "Longshore Sediment Transport on a Mixed Sand and Gravel Lakeshore." Thesis, University of Canterbury. Geography, 2006. http://hdl.handle.net/10092/1303.

Full text

Abstract:

This thesis examines the processes of longshore sediment transport in the swash zone of a mixed sand and gravel shoreline, Lake Coleridge, New Zealand. It focuses on the interactions between waves and currents in the swash zone and the resulting sediment transport. No previous study has attempted to concurrently measure wave and current data and longshore sediment transport rates on a mixed sand and gravel lakeshore beach in New Zealand. Many of these beaches, in both the oceanic and lacustrine environments, are in net long-term erosion. It is recognised that longshore sediment transport is a part of this process, but very little knowledge has existed regarding rates of sediment movement and the relationships between waves, currents and swash activity in the foreshore of these beach types. A field programme was designed to measure a comprehensive range of wind, wave, current and morphological variables concurrently with longshore transport. Four electronic instruments were used to measure both waves and currents simultaneously in the offshore, nearshore and swash zone. In the offshore area, an InterOcean S4ADW wave and current meter was installed to record wave height, period, direction and velocity. A WG-30 capacitance wave gauge measured the total water surface variation. A pair of Marsh-McBirney electromagnetic current meters, measuring current directions and velocities were installed in the nearshore and swash zone. Data were sampled for 18 minutes every hour with a Campbell Scientific CR23x data-logger. The wave gauge data was sampled at a rate of 10 Hz (0.1 s) and the two current meters at a rate of 2 Hz (0.5 s). Longshore sediment transport rates were investigated with the use of two traps placed in the nearshore and swash zone to collect sediment transported under wave and swash action. This occurred concurrently with the wave measurements and together yielded over 500 individual hours of high quality time series data. Important new insights were made into lake wave processes in New Zealand's alpine lakes. Measured wave heights averaged 0.20-0.35 m and ranged up to 0.85 m. Wave height was found to be strongly linked to the wind and grew rapidly to increasing wind strength in an exponential fashion. Wave period responded more slowly and required time and distance for the wave length to develop. Overall, there was a narrow band of wave periods with means ranging from 1.43 to 2.33 s. The wave spectrum was found to be more mixed and complicated than had previously been assumed for lake environments. Spectral band width parameters were large, with 95% of the values between 0.75 and 0.90. The wave regime attained the characteristics of a storm wave spectrum. The waves were characteristically steep and capable of obtaining far greater steepness than oceanic wind-waves. Values ranged from 0.010 to 0.074, with an average of 0.051. Waves were able to progress very close to shore without modification and broke in water less than 0.5 m deep. Wave refraction from deep to shallow water only caused wave angles to be altered in the order of 10%. The two main breaker types were spilling and plunging. However, rapid increases in beach slope near the shoreline often caused the waves to plunge immediately landward of the swash zone, leading to a greater proportion of plunging waves. Wave energy attenuation was found to be severe. Measured velocities were some 10 times less at two thirds the water depth beneath the wave. Mean orbital velocities were 0.30 m s⁻¹ in deep water and 0.15 m s⁻¹ in shallow water. The ratio difference between the measured deep water orbital velocities and the nearshore orbital velocities was just under one half (us/uo = 0.58), almost identical to the predicted phase velocity difference by Linear wave theory. In general Linear wave theory was found to provide good approximations of the wave conditions in a small lake environment. The swash zone is an important area of wave dissipation and it defines the limits of sediment transport. The width of the swash zone was found to be controlled by the wave height, which in turn determined the quantity of sediment transported through the swash zone. It ranged in width from 0.05 m to 6.0 m and widened landward in response to increased wave height and lakeward in response the wave length. Slope was found to be an important secondary control on swash zone width. In low energy conditions, swash zone slopes were typically steep. At the onset of wave activity the swash zone becomes scoured by swash activity and the beach slope grades down. An equation was developed, using the wave height and beach slope that provides close estimates of the swash zone width under a wide range of conditions. Run-up heights were calculated using the swash zone width and slope angle. Run-up elevations ranged from 0.01 m to 0.73 m and were strongly related to the wave height and the beach slope. On average, run-up exceeds the deep water wave height by a factor of 1.16H. The highest run-up elevations were found to occur at intermediate slope angles of between 6-8°. Above 8°, the run-up declined in response to beach porosity and lower wave energy conditions. A generalised run-up equation for lake environments has been developed, that takes into account the negative relationship between beach slope and run-up. Swash velocities averaged 0.30 m s⁻¹ but maximum velocities averaged 0.98 m s⁻¹. After wave breaking, swash velocities quickly reduced through dissipation by approximately one half. Swash velocity was strongly linked to wave height and beach slope. Maximum velocities occurred at beach slopes of 5°, where incident swash dominated. At slopes between 6° and 10°, swash velocities were hindered by turbulence, but the relative differences between the swash and backswash flows were negligible. At slope angles above 10° there was a slight asymmetry to the swash/backswash flow velocities due to beach porosity absorbing water at the limits of the swash zone. Three equations were developed for estimating the mean and maximum swash velocity flows. From an analysis of these interactions, a process-response model was developed that formalises the morphodynamic response of the swash zone to wave activity. Longshore sediment transport occurred exclusively in the swash zone, landward of the breaking wave in bedload. The sediments collected in transit were a heterogeneous mix of coarse sands and fine-large gravels. Hourly trapped rates ranged from 0.02 to 214.88 kg hr⁻¹. Numerical methods were developed to convert trapped mass rates in to volumetric rates that use the density and porosity of the sediment. A sediment transport flux curve was developed from measuring the distribution of longshore sediment transport across the swash zone. Using numerical integration, the area under this curve was calculated and an equation written to accurately estimate the total integrated transport rates in the swash zone. The total transport rates ranged from a minimum of 1.10 x 10-5 m³ hr⁻¹ to a maximum of 1.15 m³ hr⁻¹. The mean rate was 7.36 x 10⁻² m³ hr⁻¹. Sediment transport was found to be most strongly controlled by the wave height, period, wave steepness and mean swash velocity. Transport is initiated when waves break at an oblique angle to the shoreline. No relationships could be found between the grain size and transport rates. Instead, the critical threshold velocities of the sediment sizes were almost always exceed in the turbulent conditions under the breaking wave. The highest transport rates were associated with the lowest beach slopes. It was found that this was linked to swash high velocities and wave heights associated with foreshore scouring. An expression was developed to estimate the longshore sediment transport, termed the LEXSED formula, that divides the cube of the wave height and the wave length and multiplies this by the mean swash velocity and the wave approach angle. The expression performs well across a wide range of conditions and the estimates show very good correlations to the empirical data. LEXSED was used to calculate an accurate annual sediment transport budget for the fieldsite beaches. LEXSED was compared to 16 other longshore sediment transport formulas and performed best overall. The underlying principles of the model make its application to other mixed sand and gravel beaches promising.

APA, Harvard, Vancouver, ISO, and other styles

19

Dai, Ting-Yu, and 戴廷育. "Field study of wave run-up." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/ub3qh9.

Full text

Abstract:

碩士
國立中山大學
海洋環境及工程學系研究所
97
It is important to estimate the quantity of wave run-up and overtopping in seawall design. Previous study on the investigations of run-up is carried out mostly in the laboratories, it seldom perform in field measurements. About previous wave run-up equation can’t accurately estimate run-up elevation. According to run-up data, this study hope that it can make the formula to meet the actual local situation. It can have a better reference by designing coastal structures. This paper study wave run-up during five typhoons by Kalmaegi ,Fung-Wong,Nuri, Hagupit,and Jangmi. It measuring wave height , water level,and topography. These data show that the run-up elevation in bay higher than in breakwater. It shows that wave pass through a submerged breakwater can decay wave height. Analysis of measured data and found that when the wave height is about 1~4 meter with 1/(H0/L0)0.5 has a good correlation. It similar to some past researchers. Experience equations close to measured value when wave height smaller than 4 meter. When wave height more than 4 meter, the empirical prediction value is larger than measured value. Wave run-up doesn’t have good theory, and experience equations different about every field. The empirical equations depends on the scene to investigate the effects of various parameter.

APA, Harvard, Vancouver, ISO, and other styles

20

Curi, Fuad. "Reliability analysis of wave run-up." Thesis, 2002. http://hdl.handle.net/2429/12054.

Full text

Abstract:

Assessing the run-up arising from ocean waves as they reach a coastal or offshore structure is an important aspect of engineering projects. By combining formulations for calculating the run-up of regular waves with wave statistical descriptions, a procedure is implemented to assess wave run-up in random sea conditions. This procedure uses the First and Second Order Reliability Methods. It is applied to four cases representing common coastal structures: vertical wall, vertical cylinder, smooth impermeable slope and rough permeable slope. The results of the reliability methods are compared with two other methodologies commonly used in coastal and ocean engineering. The first methodology (Method I) consists of calculating the significant wave height for a given return period from the long-term distribution of storms. Then, the maximum wave height corresponding to the significant wave height, and its corresponding wave run-up are obtained. Method II consists of obtaining a long-term distribution of individual wave heights, so that the maximum wave height for a given return period can be directly calculated. Then, the corresponding wave run-up is determined as in Method I, by applying regular wave formulations to the maximum wave height. Method I provides lower values of wave run-up than all other methods, while Method II provides the highest values of wave run-up, and proves to be dependent on the severity factor, a parameter characterizing the long-term distribution of storms. Results show that both the First and Second Order Reliability Methods correspond with Method II when the values of the severity factor are low, but approach Method I as the value of the severity factor increases. The wave run-up is found to depend on the characteristics of the structure in place, such as cylinder radius, slope angle and surface permeability, as well as on such sea conditions as severity factor and the duration and frequency of storms. The wave run-up to significant wave height ratio is independent of the return period for the four cases studied here. This ratio results in a non-dimensional form of wave run-up that appears to provide useful means for describing the phenomenon.

APA, Harvard, Vancouver, ISO, and other styles

21

Chen, Yung-Tsang, and 陳永倉. "Numerical investigation of solitary wave propagation and run-up." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/91458807940996198609.

Full text

Abstract:

碩士
國立臺灣海洋大學
海洋環境資訊學系
95
Abstract Tsunamis are usually generated by the impulsive seafloor movement in deep water due to undersea earthquakes. When tsunami propagates at speed of 150~215m/s to the nearshore, larger amplitude due to shoaling and destructive force acting on the coastal area will lead to a serious damage. Due to their similarities, solitary waves are often used to investigate the characteristics of tsunami. In particular, the multi-layer Boussinesq model developed by Lynett and Liu (2004) was employed to investigate the dynamics of solitary wave evolutions over a composite linear topography and run-up motions on a uniform sloping bottom in this study. The moving boundary algorithm proposed by Lynett et al. (2002) was introduced into present model to simulate the run-up motions. In addition to compare our numerical results with existing laboratory data and analytical theory, the effects of bed slopes and incident wave nonlinearity are discussed both for the cases of breaking and non-breaking waves. Good agreements are found between our numerical results and available experimental data. Furthermore, the runup height increases as bed slope increases for non-breaking waves, while runup height decreases with decrease of bed slope. This result confirms the finding of Li and Raichlen (JFM, 2002) using different numerical model. In summary, the Boussinesq model has been proved to well simulate the evolution of solitary waves in this study in many cases. However, due to lacking of experimental data, some numerical findings in this study need to be further verified.

APA, Harvard, Vancouver, ISO, and other styles

22

Li, Ying. "Tsunamis : non-breaking and breaking solitary wave run-up." Thesis, 2000. https://thesis.library.caltech.edu/6110/1/Li_y_2000.pdf.

Full text

Abstract:

This study considers the run-up of non-breaking and breaking solitary waves on a smooth sloping beach. A non-linear theory and a numerical model solving the non-linear shallow water equations (NLSW) were developed to model this physical process. Various experiments to obtain wave amplitude time-histories, water particle velocities, wave free-surface profiles, and maximum run-up were conducted and the results were compared with the analytical and numerical models. A higher order theoretical solution to the non-linear shallow water equations, which describes the non-breaking wave characteristics on the beach, was sought and presented in this study. The solution was obtained analytically by using the Carrier and Greenspan (1958) hodograph transformation. It was found that the non-linear theory agreed well with experimental results. The maximum run-up predicted by the non-linear theory is larger than that predicted by Synolakis (1986) at the order of the offshore relative wave height for a given slope. This correction for non-breaking waves on beach decreases as the beach slope steepens, and increases as the relative incident solitary wave height increases. A unique run-up gage that consists of a laser and a photodiode camera was developed in connection with this study to measure the time-history of the tip of the run-up tongue of a non-breaking solitary wave as it progresses up the slope. The results obtained with this run-up gage agree well with other measurements and provides a simple and reliable way of measuring run-up time histories. The run-up of breaking solitary waves was studied experimentally and numerically since no fully theoretical approach is possible. The wave characteristics such as wave shape and shoaling characteristics, and, for plunging breakers, the shape of the jet produced are presented. The experimental results show that wave breaking is such a complicated process that even sophisticated numerical models cannot adequately model its details. Two different plunging wave breaking and resultant run-up were found from the experiments. The point, where the tip of the incident jet produced by the plunging breaking wave impinges determines the characteristics of the resulting splash-up. If the jet impinges on a dry slope, no splash-up occurs and the plunging breaker simply collapses. If the impingement point is located on the free-surface, splash-up including a reflected jet is formed, which further increases the turbulence and energy dissipation associated with wave breaking. It is hypothesized that both clockwise and counter clockwise vortices may be generated by the impinging plunging jet and the reflected jet associated with the splash-up when the jet impinges on the front face of a breaking wave or on the still water surface in front of the wave. If only the run-up process and maximum run-up are of interest, the wave and the water flow produced after breaking can be simplified as a propagating bore, which is analogous to a shock wave in gas dynamics. A numerical model using this bore structure to treat the process of wave breaking and propagation was developed. The non-linear shallow water equations were solved using the weighted essentially non-oscillatory (WENO) shock capturing scheme employed in gas dynamics. Wave breaking and propagation is handled automatically 1w this scheme and no ad-hoc term is required. A computational domain mapping technique proposed by Zhang (1996) is used in the numerical scheme to model the shoreline movement. This numerical scheme is found to provide a somewhat simple and reasonably good prediction of various aspects of the run-up process. The numerical results agree well with the experiments corresponding to the run-up on a. relatively steep slope (1:2.08) as well as on a more gentle slope (1:19.85). A simple empirical estimate of maximum run-up based on energy conservation considerations is also presented where the energy dissipation associated with wave breaking was estimated using the results from the numerical model. This approach appears to be useful and the maximum run-up predicted agrees reasonably well with the experimental results. The splash-up of a solitary wave on a vertical wall positioned at different locations on a gentle slope was also investigated in this study to understand the degree of protection from tsunamis afforded by seawalls. It was found that the effect of breaking wave kinematics offshore of the vertical wall on the splash-up is of critical importance to the maximum splash-up. The maximum slope of the front face of the wave upon impingement of the wave on the wall, which represents the maximum water particle acceleration, was important in defining the maximum sheet splash-up as well as the trend for splash-up composed of drops and spray.

APA, Harvard, Vancouver, ISO, and other styles

23

Yu-TingLee and 李昱霆. "Mitigation of long wave run-up using submerged breakwaters." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/13482108688928894123.

Full text

Abstract:

碩士
國立成功大學
水利及海洋工程學系
104
SUMMARY Taiwan is an island located in the Ring of Fire such that earthquakes occurred frequently. Observing the surrounding seabed topography, northeast and southwest coastal area of Taiwan is relatively gentle and extensively flat, which is suitable for the shoaling and amplification processes of tsunamis, which means that Taiwan is a high potential area of tsunami catastrophe. Recalling the 2004 India Ocean tsunami and the 2011 Tohoku earthquake tsunami, tsunami were caused by mega scale earthquakes that brought tremendous catastrophe in the disaster regions. It is thus of great importance to develop innovative approach to achieve the reduction and mitigation of tsunami hazards. We propose a concept of using multiple submerged breakwaters to mitigate tsunami-like long wave by means of solitary waves. However, previous investigations of submerged breakwaters under long waves considered that the target obstacles built on a flat bottom. In this study, we installed submerged breakwaters on a mild slope instead to discuss the possible mitigation of run-up heights. Experiments were performed in a glass-walled wave tank located at the Tainan Hydraulics Laboratory, National Cheng Kung University. The slope is 1/20 and solitary waves is used to simulate extremely long wave such as tsunami due to its hydraulics similarity. The subject of this study is to use submerged breakwaters to mitigate long wave energy, enhance the breaking processes due to shoaling and, in part, to reflect the incoming wave due to the presence of obstacle. When waves are breaking, lots of air bubbles were entrained into the testing fluid and the fluid becomes turbulent. By this process, submerged breakwaters once again reduce long wave energy. In this study, we used Max. run-up heights to judge different scenario’s utility. When waves are breaking, lots of air bubbles were entrained into the testing fluid making the fluid to be turbulent, in this way, submerged breakwaters will further reduce the wave energy of incoming waves. Here, we use maximum run-up heights to judge the capabilities of different configuration of breakwaters. The optimal single breakwater scenario in our teat can mitigate about 70% run-up height (hs= 0 cm, Xb= 0 cm, ε=0.11), and best dual breakwater scenario is 90% (hs= 0 cm, Xb= 0＆112 cm, ε= 0.11).Therefore, submerged breakwaters are indeed possible to reduce long-wave energy. In addition, we use a state-of-the-art measuring technique Bubble Image Velocimetry, which features non-intrusive and image-based measurement. The measured wave kinematics in the highly aerated region due to solitary-wave shoaling, breaking and uprush can be quantitated. The measured results in terms of velocities will be used to complete the conjunction with run-up height reduction. Key words: solitary wave, run-up, breakwater, BIV

APA, Harvard, Vancouver, ISO, and other styles

24

Cheng, Li-Chung, and 鄭力中. "Numerical Simulation by FLOW-3D on the Wave Set-up and Run-up." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/x4q9m4.

Full text

Abstract:

碩士
國立中山大學
海洋環境及工程學系研究所
105
The calculation of run-up is usually estimated by the offshore maximum wave height. Nevertheless, the higher wave height with the same period result in larger wave steepness. A wave will break earlier by the shoaling effect with larger wave steepness. On the contrary, A wave will break later with smaller wave steepness. Therefore, the major issue of this study is to analysis whether the wave result in larger run-up and set-up with larger wave steepness or not. A computational fluid dynamics software called “FLOW-3D” is used to simulate this study. There are three kinds of slope 1/10, 1/20 and 1/30 used for impermeable bottom. An impermeable embankment is set at the end of the slope. Observe and record related data such as mean water level, run-up, etc. by changing period, wave height and slope. According to the results of FLOW-3D, the ratio of mean water level in front of embankment to incident wave height for smaller breaking depth is larger than larger breaking depth. The most former research indicates that slope is a crucial parameter for wave run-up. Nevertheless, slope effects wave run-up slightly on a gentle slope. Wave run-up displays positive correlation to wave period on a steep slope. On a gentle slope, wave run-up is not related to wave period. The consequences of the comparison between model and experience indicate each experimental equation may show the exacter solution at specific slope. Keywords: wave break, wave set-up, wave run-up, numerical simulation, FLOW-3D

APA, Harvard, Vancouver, ISO, and other styles

25

Li, Yi-Syuan, and 李宜軒. "Run-up and wave height evolution of breaking solitary waves on sloping beaches." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/19855981856946379570.

Full text

Abstract:

碩士
國立成功大學
水利及海洋工程學系碩博士班
95
This is a study of runup and wave height evolution of breaking solitary waves on sloping beaches. The process of wave height evolution and the time series water level variation from shoaling to runup were observed through laboratory experiments. The experiments including three different slopes 1/20, 1/40 and 1/60 were conducted in Super Tank of Tainan Hydraulic Laboratory. Solitary waves were generated by moving the wave plate forward in the manner of ramp trajectory(R-wave) and solitary-wave trajectory(solitary wave). There are three water depth on slope 1/60 solitary-wave trajectory to discuss influences of water depth. Results show that there is no distinct difference between R-wave and solitary wave on wave breaking, but solitary wave is a little larger than R-wave on runup height. When slopes are steeper Hb/hb and R/h0 would larger, this is agree with previous experiments data. Only Hb/h0 and Hb/H0 seem had no obviously change with slope. The influence of water depth variations are not clearly. The relation between R/h0 and Hb/h0 is linear, and that prove runup and wave breaking has a highly correlation.

APA, Harvard, Vancouver, ISO, and other styles

26

FANG, YONG-SHENG, and 方勇勝. "Wave run-up and pressures on a smooth sloping seawall." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/61728704582778987220.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Lan, Tsung-Yi, and 藍聰義. "An Experimental Study on Wave Run-up over a Seawall." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/48wsvw.

Full text

Abstract:

碩士
國立成功大學
水利及海洋工程學系碩博士班
92
This paper is aimed to investigate the relationship between wave run-up over the seawall and the physical properties of outer-layer structure. To achieve this, a series of experimental tests were conducted. In these tests, a total of five types of porous material were disposed, respectively, on the surface of the seawall model, then wave run-up over the porous material were measured under various wave conditions. Two different seawall slopes were included, and five material thickness were adopted. Based on experimental results, it is observed that wave run-up depends apparently on relative thickness of the porous material if the relative thickness is small than 0.2. The wave run-up decreases as relative thickness increases. However, if relative thickness becomes greater than 0.2, wave run-up would decrease no more. Therefore, it is realized that waves coming up a seawall consume their energy in the porous material only within a relative thickness of 0.2. As for the porosity, it is indicated that the wave run-up decreases with increasing porosity, with wave run-up decreasing rate depending on relative water depth. As relative water depth decreases, the porosity would play a more important role on wave run-up over the seawall. Further, it is found that the coefficient of permeability is directly propotional to the porosity, therefore, the wave run-up also decreases as coefficient of permeability increases. Finally, formulas relating wave run-up to either porosity or permeability are suggested.

APA, Harvard, Vancouver, ISO, and other styles

28

Zhan-JunHou and 侯展鈞. "An Extension of Mild-Slope Equation for Simulating Wave Run-up." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/71811964209480149983.

Full text

Abstract:

碩士
國立成功大學
水利及海洋工程學系碩博士班
101
A numerical model was developed for simulating wave run-up after wave breaking over a sloping beach. This model is decoupled by the wave model of EEMSE (evolution equation for mild-slope equation) as well as the wave run-up model of LSWWE (linear shallow-water wave equations). Experimental data of Mase et al. (1984) and Hsu et al. (2012) were used to perform the regression analysis. The result lead to a regression formula which was applied as the input wave conditions for the prediction of wave run-up as LSWWE was used. The model was applied to simulate wave run-up for the cases of wave propagation are 1D sloping beach and 2D planar beach. Numerical results showed that the present model is capable of describing the dynamic process of wave run-up. It is found that the wave run-up increases with the decrease of beach slope. A case study was successfully performed at Dapengwan for practical applications.

APA, Harvard, Vancouver, ISO, and other styles

29

Chen, Yueh-Heng, and 陳玥亨. "Experiments on the Influence of Wave Breaking and Bragg Reflection on Wave Run-Up by Submerged Breakwaters." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/6t99ju.

Full text

Abstract:

碩士
國立中興大學
土木工程學系所
106
Coastal environmental protection nowadays is an important issue in coastal field. The coastal protection countermeasures have been evolved into multiple functions. Submerged breakwater was recognized that it may reduce wave incident energy but also preserve coastal landscape. General submerged breakwater forces the wave breaking on the top of the breakwaters to decay the incident wave energy to achieve the effect of coastal protection. Another arrangement is the series submerged breakwaters to induce larger wave reflection and reduce wave transmission, called Bragg Reflection, to protect the coastal zone. This study conducted a series of hydraulic experiments using both regular wave and irregular wave to investigate the effects on coastal protection using different arrangements of submerged breakwaters. One is a single submerged breakwater with enough height to occur wave breaking on its crown top, and the other one is the Bragg reflection arrangement using a series submerged breakwaters without wave breaking. The spatial distribution of wave height, the coefficients of wave reflection and wave transmission, and the wave run-up on the mild slope behind the submerged breakwaters were analyzed. The results of regular waves were also compared with the numerical simulated results. The experimental results show that the Bragg Reflection arrangement can reduce wave height behind the series submerged breakwaters due to higher wave reflection from breakwaters. It is found that the numbers of series of submerged breakwaters increases, the phenomenon of Bragg Reflection is more obvious, i.e. the wave reflection coefficient increases and the wave transmission and wave run-up decrease. For that of single higher submerged breakwater, it results in less wave reflection, transmission and wave run-up causing by the wave breaking, when comparing to the arrangements of Bragg reflection with four submerged breakwaters. This study concludes that the single higher submerged breakwater with wave breaking in reducing wave transmission and wave run-up may be effective rather than the use of four submerged breakwaters with Bragg reflection arrangement.

APA, Harvard, Vancouver, ISO, and other styles

30

Lee, Yen-Chen, and 李彥枝. "Using a Vertically-stratified Porous Apron to Reduce Wave Run-up over a Seawall." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/84595074849635341312.

Full text

Abstract:

碩士
國立成功大學
水利及海洋工程學系碩博士班
91
This paper is aimed to continue the efforts of Chen (2002), trying to verify the theory developed by Twu et al. (2001). This work is performed by conducting experimental tests on wave run-up over a seawall with various aprons installed in front of the seawall. The aprons are made of porous material with different length, height and number of slices. It is shown that the wave run-up over the seawall decreases with increasing porosity if a single-sliced apron is used. However if a double-sliced is adopted to replace a single-sliced apron, the wave run-up can be reduced further. For instance, if an apron of double-sliced F-type apron (porosity(1)=0.77, porosity(2)=0.41) or G-type (porosity(1)=0.77, porosity(2)=0.45) is used rather than a single-sliced D-type (porosity=0.77) in front of the seawall with slope of 1:2, the wave run-up can be reduced by 0.8%~1.5% for an increase of △b/h=1. Similarly, if a double-sliced H-type (porosity(1)=0.90, porosity(2)=0.41) or I-type (porosity(1)=0.90,porosity(2)=0.45) or J-type (porosity(1)=0.90, porosity(2)=0.77) is used instead of a single-sliced E-type (porosity=0.9), then the wave run-up would be reduced by 1.3%~2.2% for an increase of △b/h=1. For a seawall with slope 1:3, the reduction in wave run-up would be 0.2%~1.8%、1%~3.5%, respectively in the pervious two cases。 Moreover, the wave run-up over the seawall can be further reduced if a triple-sliced apron is employed. For instance, if an apron of triple-sliced K-type (porosity(1)=0.9、porosity(2)=0.77、porosity(3)=0.41) or L-type (porosity(1)=0.9、porosity(2)=0.77、porosity(3)=0.45) is installed in front of a seawall with slope of 1:2. The wave run-up could be reduced by 0.3%~1% for an increase of △b/h=1, as compared to a double-sliced one (J-type). For a seawall with slope 1:3, the reduction in wave run-up would be 0.2%~2.3%. The results show that by using the porous material as an apron in front of seawall, wave run-up over the seawall can be reduced and the reduced level is increased with the increase of porosity and the number of vertically-stratified slices.

APA, Harvard, Vancouver, ISO, and other styles

31

Hsu, Chen-Jui, and 許晟睿. "UAV observation and analytical approach to the wave run-up on a natural beach." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/7shf96.

Full text

Abstract:

碩士
國立交通大學
土木工程系所
107
Wave run-up is an important factor in the coastal sediments. Few previous studies on in-site wave run-up were fulfilled due to complexity of run-up in a natural beach and limited for in-site observation. In this study an unmanned aerial system was set up to have living recording the whole process of wave run-up. Through coordinate transformation between image coordinates and world coordinates for each photo instant wave run-up along the shoreline were computed and some analytical solution were proposed for the motion to explore the characteristics of bore run-up. Bore run-up is mainly affected by the forebeach slope and bottom friction, and the varied characteristics of bore run-up on a natural beach. The natural beach is suitably described by a linear or a bilinear equation in this study. A fixed bore or a varied bore is assumed to move on the beach in the theoretical . Analytical solutions of such bores are proposed for the run-up of two kinds of expressed beaches based on the motion equation proposed by Kirkgöz. Comparison of the run up of bore with that by empirical formula of Mase and Iwagaki (1984) shows that if the bore is fixed, the mean squared errors of uniform slope and of bilinear slope are 3.8% and 5.3%, and the biases of such slopes are 2.8% and 3.5%, respectively. If the bore is varied, two mean squared errors are 9.0% and 8.9%, the biases are 8.9% and 8.4%, respectively, for such slopes. All analytical solutions of the bore run-up on the flood are closer to the measured ones than those on the same level during ebb. The mean squared errors between the measured run-ups with the solutions for the beach expressed by two kinds of slopes are 11.6% and 11.3%, respectively, corresponding biases are 8.8% and 8.5%.

APA, Harvard, Vancouver, ISO, and other styles

32

Cheng, Wei-Jei, and 程偉傑. "Reducing Effect On the Wave Run-up Over the Seawall by a Porous Apron." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/3k2x8w.

Full text

Abstract:

碩士
國立成功大學
水利及海洋工程學系碩博士班
90
This study is to investigate the reducing effect on the wave run-up over the seawall by a porous apron .The apron is designed to serve two major purposes. One of them is to protect the seabed at the toe of the seawall from scouring. The other is to attenuate the incoming waves. To achieve this, the bottom of the apron is made of a solid plate. And upper part of it must be a porous structure. Three types of porous media have been used as the material for the upper part of the apron. They are referred to as material A, B and C, and their porosities are 0.9, 0.77 and 0.45, respectively. Then experimental tests are conducted using three depths of submergence, four different apron lengths and two different seawall slopes. It is concluded that the apron with larger porosity would raise smaller wave run-up over the seawall. Moreover, as the depth of submergence decreases, the length increases, the wave run-up will be reduced.

APA, Harvard, Vancouver, ISO, and other styles

33

Liang, Luo Gwo, and 駱國良. "The study of the effect of roughness to wave run-up on composite slope." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/19350207926599499144.

Full text

Abstract:

碩士
國立中央大學
土木工程研究所
82
The effect of roughness of composite slopes on the mitigation of wave run-up is explored in this study. Model tests are performed in a wave flume with irregular-wave conditions. The parameters affect the wave run-up such as roughness, berm width, and water depth are analyzed based on the test data. There are some relationships between the roughness and relative run-up. When the roughness is larger and the berm width is longer, the relative wave run-up is slower. The water depth in front of the levee deeply influences the relative run-up height. In this study, the relative run-up increases when water depth excedes the berm surface. The spectrum analysis shows that the reducing of run-up is much more significant in small waves than that in large waves. It means that the high- frequency component of incoming wave spectrum is transfered to the low-frequency component of the wave run up. The amount of transfer between two wave spectrums is related to the roughness and berm width of the levee.

APA, Harvard, Vancouver, ISO, and other styles

34

Shih, Han-Chen, and 施翰辰. "A Numerical Study on the Influence of Wave Breaking and Bragg Reflection on Wave Run-Up by Submerged Breakwaters." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/vhjut3.

Full text

Abstract:

碩士
國立中興大學
土木工程學系所
106
The purpose of this study is aimed to investigate the influence of wave breaking and Bragg reflection on the wave run-up by submerged breakwaters. This study used computational fluid dynamics to analyze the characteristics of wave flow field, reflection coefficient, transmittion coefficient and run-up height. The numerical model is based on general Reynolds-averaged Navier-Stokes equations associated with renormalization group turbulent closure model by using volume of fluid technique, which are implemented by FLOW-3D. The experimental data by Ting and Kirby (1994) and Mase et al. (1995) were used to verify numerical result. The results showed good agreement between the numerical simulation and experiment of the variations of wave height along the slope and Bragg reflection effect respectively. The results show that wave reflection coefficient and turbulent dissipation rate increased with the increasing of series submerged breakwaters numbers, but wave transmission coefficient and run-up height displayed decreased with the increasing of series submerged breakwaters numbers. Due to wave breaking phenomenon on the higher submerged breakwaters, it leads to higher wave reflection coefficient and lower wave transmission coefficient caused by wave turbulent energy dissipation.

APA, Harvard, Vancouver, ISO, and other styles

35

Shih, Shyuer-ming. "Processes of sea-cliff erosion on the Oregon coast : from neotectonics to wave run-up /." 1992. http://hdl.handle.net/1957/12948.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Lin, Dai-Wei, and 林岱瑋. "Laboratory Simulation Study of Wave Run-up and Temperature ariation on Seawall by Applying Pervious Concrete." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/45029758978577136198.

Full text

Abstract:

碩士
朝陽科技大學
營建工程系碩士班
99
Pervious concrete is a special type of porous concrete with high permeability, multi-porous and rough surface characteristics. The U.S. Environmental Protection Agency (EPA) believes that properly using pervious concrete in pavement is the best method to control the first-flush pollution and storm water management. The permeable concrete contains a lot of holes, which can not only keep water to enhance the capability of exchanging heat and water between surface and air, but also can decline the surface temperature to reduce the urban heat island effect. According to the recent report of ACI 522R-06 in the US, pervious concrete can be used in harbors construction, including shore protection structures, seawalls and artificial reefs. In order to have information on applying pervious concrete on seawall run-up and the material temperature changes during the heated processing, the study focus on wave run-up test and temperature rising test to preliminary understand the energy dissipation for applying pervious concrete on sea structures and its temperature characteristics, through comparing the experimental results of pervious and asphalt concrete. From the laboratory simulation seawall results, it shows that the run-up heights of the pervious concrete specimens with three different slopes are lower than the run-up heights of the ordinary concrete specimens with three different slopes do. In different flowing rates, the run-up heights of pervious concrete specimens are lower than the run-up heights of concrete specimens do. From the designed temperature test, the results indicate that the speeds of heating and cooling rates of pervious concrete specimens are close to the heating and cooling rate of asphalt concrete; both of them are faster than normal concrete does.

APA, Harvard, Vancouver, ISO, and other styles

37

Chih-HsinChen and 陳志欣. "Simulations of Wave Run-up and Overtopping at Irregular Coastal Structures Using Mass-Conserved Boundary Method." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/10429162056479111547.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Chen, Chien-Chih, and 陳建志. "An Experimental Study on Wave Run-up over a Seawall with porous cover-layer and front apron." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/70013894777696475180.

Full text

Abstract:

碩士
國立成功大學
水利及海洋工程學系碩博士班
93
The cover-layer and the apron of a seawall were considered to be placed with porous structure. Then the effects of the physical property of the porous structure on the wave run-up over the seawall were investigated experimentally. In the experiments, the thickness of the porous cover-layer was chosen as 0.2 times water depth. Then the wave run-up tests were conducted at various wave conditions, having the thickness and length of the apron changed from case to case. A total of four types of porous structures were adopted and two kinds of seawall slopes were used. The experimental results showed that the wave run-up over the seawall decreases as porosity increases. Moreover, if seawall slope becomes milder, the porous structure would reduce the wave run-up even further. Adopting porous structure as cover-layer and apron of seawall would reduce a larger amount of wave run-up in small water depth than in deep water depth. Increasing the thickness of the apron would influence more on reducing the wave run-up than increasing its thickness does. Finally, regression analysis was conducted and wave run-up formulas were established relating to those factors such as wave steepness, porosity, relative thickness and relative length of apron.

APA, Harvard, Vancouver, ISO, and other styles

39

Chen陳靖夫, Jing-Fu, and 陳靖夫. "The CFD Simulation of Run-Up Heights and Wave Loads by Considering the Foundation Types of Offshore Wind Turbines." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/98808373310005121824.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Izadparast, Amir Hossein. "Semi-empirical Probability Distributions and Their Application in Wave-Structure Interaction Problems." Thesis, 2010. http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8763.

Full text

Abstract:

In this study, the semi-empirical approach is introduced to accurately estimate the probability distribution of complex non-linear random variables in the field of wavestructure interaction. The structural form of the semi-empirical distribution is developed based on a mathematical representation of the process and the model parameters are estimated directly from utilization of the sample data. Here, three probability distributions are developed based on the quadratic transformation of the linear random variable. Assuming that the linear process follows a standard Gaussian distribution, the three-parameter Gaussian-Stokes model is derived for the second-order variables. Similarly, the three-parameter Rayleigh-Stokes model and the four-parameter Weibull- Stokes model are derived for the crests, troughs, and heights of non-linear process assuming that the linear variable has a Rayleigh distribution or a Weibull distribution. The model parameters are empirically estimated with the application of the conventional method of moments and the newer method of L-moments. Furthermore, the application of semi-empirical models in extreme analysis and estimation of extreme statistics is discussed. As a main part of this research study, the sensitivity of the model statistics to the variability of the model parameters as well as the variability in the samples is evaluated. In addition, the sample size effects on the performance of parameter estimation methods are studied. Utilizing illustrative examples, the application of semi-empirical probability distributions in the estimation of probability distribution of non-linear random variables is studied. The examples focused on the probability distribution of: wave elevations and wave crests of ocean waves and waves in the area close to an offshore structure, wave run-up over the vertical columns of an offshore structure, and ocean wave power resources. In each example, the performance of the semi-empirical model is compared with appropriate theoretical and empirical distribution models. It is observed that the semi-empirical models are successful in capturing the probability distribution of complex non-linear variables. The semi-empirical models are more flexible than the theoretical models in capturing the probability distribution of data and the models are generally more robust than the commonly used empirical models.

APA, Harvard, Vancouver, ISO, and other styles

41

Chang, Yu hsuan, and 張裕弦. "Study on Run-up of Solitary Waves over Sloping Bottoms." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/54357992687872978004.

Full text

Abstract:

博士
國立成功大學
水利及海洋工程學系碩博士班
96
The run-up of solitary waves was investigated experimentally and theoretically in this study. A series of large-scale laboratory experiments was carried out in the Super Tank (300 m × 5 m × 5.2 m) at Tainan Hydraulics Laboratory. On the plane beach of three slopes 1:20, 1:40 and 1:60, the wave evolution and maximum run-up heights of solitary waves were experimentally investigated by two different controls of wave generation as ramp-trajectory and Goring’s (1978) method. Another series of large-scale experiments was performed on a 1:20 sloping bottom to acquire more in-depth data which presented the distribution of hydrodynamic pressure and flow velocity in the run-up zone of a solitary wave. The measured data are employed to re-examine existing formula that include breaking criteria, amplitude evolution and run-up height. The comparison between the solitary wave and the N wave suggests that the dispersion effect of N wave is determined on the shape of leading wave. As the shape of leading wave approach solitary wave, the characteristics on wave evolution and run-up of N wave are more similar to that of solitary wave. The re-acceleration of the advancing wave front was filmed when 2004 tsunami happened in Sumatra, and which was also observed in such experiments. The run-up flow and related pressure of solitary waves breaking on a 1:20 plane beach were further investigated experimentally in super tank. The swash flow measurement of flow velocity is briefly discussed and compared with an existing analytical solution. By incorporating an analytical solution, the hydrodynamic pressure for a quasi-steady flow state is determined and compared with laboratory data. An approximate drag coefficient, in the circular plane that is normal to the flow direction, is suggested for the evident extra pressure exerted by the impact of a solitary wave. Based on the asymptotic solution of water depth close to the run-up tip, a theoretical approach considering hydraulic pressure in the run-up process of breaking solitary waves was developed. The pressure gradient force is considered in the kinematic run-up process description by adding a pressure term in the force balance. This term is added on the leading edge within the run-up tongue. A depth equation is proposed as the description of the swash depth near run-up tip, based on the Shen & Meyer (1963) asymptotic solution of water depth close to the front, and is further applied to calculate the pressure gradient force acting on the thinning leading edge. An initial-value problem of run-up motion was constructed and solved using a semi-analytical solution technique. Experimental measurements clearly show that the proposed depth equation can reasonably describe the swash depth near run-up tip. Good agreement between modeled and observed swash behavior suggest that the present model can adequately estimates the maximum run-up height.

APA, Harvard, Vancouver, ISO, and other styles

42

Lee, Yi-Fang, and 李宜芳. "Run-up and Overtopping of Solitary Waves around a Seawall." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/74609516404949450411.

Full text

Abstract:

碩士
國立成功大學
水利及海洋工程學系碩博士班
97
In present study a 2-D numerical viscous wave model was developed and applied to represent propagation of a solitary wave over a seawall on a real sea bed including run-up or overtopping phenomena. The numerical model solved the unsteady, two dimensional Reynolds Average Navier-Stokes (RANS) equation and the turbulent model ( model) for simulating the realistic fluid. A hybrid particle level set method was incorporated to capture the complex free surface. An immersed boundary method was adapted to present the behavior of fluid flow in the vicinity of irregular solid boundary in the Cartesian coordinate system. The numerical results were demonstrated by a serious of numerical experiments, such as the Zalesak’s problem, cavity flow problem, and a uniform flow pass through a cylinder. Finally, the present wave model was conducted to simulate the surface evolution as a solitary wave attacked the seawall of Taidung, Fugang and Sanhe of Taidung Taiwan. Including wave shoaling, run-up, run-down and overtopping phenomena were observed in numerical results and the relationships between run-up height and incident wave heights, the distance from wave incident to a seawall etc. were discussed briefly.

APA, Harvard, Vancouver, ISO, and other styles

43

Li-FanYang and 楊立帆. "Numerical Simulation of Regular Waves Run-up on a Sloping Bed." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/04267972537408288033.

Full text

Abstract:

碩士
國立成功大學
水利及海洋工程學系碩博士班
100
In present study, a 2-D numerical viscous wave flume was applied to represent the characteristic of wave and flow field as regular waves run-up on a sloping bed. The unsteady, two-dimensional Reynolds Averaged Navier-Stokes (RANS) equations and the turbulence model ( model) were solved for simulating the behavior of real fluid. The level set method and the particle level set method were adopted to capture the complex free surface evolution. The Mass-Conserved Boundary Method (MCBM) was applied to represent the fluid-solid interaction in the vicinity of irregular solid boundary under the Cartesian grid system. This study is proposing to investigate the wave run-ups with different incident regular waves and bed slopes. The free-surface evolutions, the flow fields and the wave pressures on the sloping bed are discussed. Partial standing waves and the reverse flows within boundary layer are reproduced in this study. The evolutions of wave pressure on the sloping bed are related to the instantaneous wave elevations. Furthermore, steady recirculating cell are detected from the mean velocity field upon the sloping bed.

APA, Harvard, Vancouver, ISO, and other styles

44

Hung, Chung Hung, and 洪俊宏. "An Experimental Study for Irregular Waves Run-up on Coastal Structure." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/78142839205210361972.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Lin, Duo-min. "Run-up and nonlinear propagation of oceanic internal waves and their interactions." Thesis, 1996. https://thesis.library.caltech.edu/5066/1/Lin_dm_1996.pdf.

Full text

Abstract:

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. A weakly nonlinear and weakly dispersive oceanic internal long wave (ILW) model, in analogy with the generalized Boussinesq's (gB) model, is developed to investigate generation and propagation of internal waves (IWs) in a system of two-layer fluids. The ILW model can be further derived to give a bidirectional ILW model for facilitating calculations of head-on collisions of nonlinear internal solitary waves (ISWs). The important nonlinear features, such as phase shift of ISWs resulting from nonlinear collision encounters, are presented. The nonlinear processes of reflection and transmission of waves in channels with a slowly varying bottom are studied. The terminal effects of IWs running up submerged sloping seabed are studied by the ILW model in considerable detail. Explicit solution of the nonlinear equations are obtained for several classes of wave forms, which are taken as the inner solutions and matched, when necessary for achieving uniformly valid results, with the outer solution based on linear theory for the outer region with waves in deep water. Based on the nonlinear analytic solution, two kinds of initial run-up problems can be solved analytically, and the breaking criteria and run-up law for IWs are obtained. The run-up of ISWs along the uniform beach is simulated by numerical computations using a moving boundary technique. The numerical results based on the ILW model are found in good agreement with the run-up law of ISWs when the amplitudes of the ISWs are small. The ILW model differs from the corresponding KdV model in admitting bidirectional waves simultaneously and conserving mass. This model is applied to analyze the so-called critical depth problem of ISWs propagating across a critical station at which the depths of the two fluid layers are about equal so as to give rise to a critical point of the KdV equation. As the critical point is passed, the KdV model may predict a new upward facing ISW relative to a local mean interface is about to emerge from the effects of disintegrating original downward ISW. This phenomenon has never been observed in our laboratory. Numerical results are presented based on the present ILW model for ISWs climbing up a curved shelf and a sloping plane seabed. It is shown that in the transcritical region, the behaviour of the ISWs predicted by the ILW model depends on the relative importance of two dimensionless parameters, [...], the order of ISW wave slope, and s, the beach slope. For s >> [...], the wave profile of ISWs exhibits a smooth transition across the transcritical region; for s << [...], ISWs emerge with an oscillatory tail after passing across the critical point. Numerical simulations based on the ILW model are found in good agreement with laboratary observations. Finally, conclusions are drawn from the results obtained in the present study based on the ILW model.

APA, Harvard, Vancouver, ISO, and other styles

46

Ta-YuHuang and 黃大祐. "Simulation of Propagation and Run-up of Landslide-induced Waves Using Meshless Method." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/40233346145865550612.

Full text

Abstract:

碩士
國立成功大學
水利及海洋工程學系碩博士班
100
A two-dimensional numerical model using radial basis functions (RBFs) and collocation points for resolving the Laplace equation is presented in this study. This method is a general meshless method called RBF collocation method. The basic concept of RBF collocation method is to approximate the solution of a PDE as a linear combination of RBFs. The main framework of the present model is developed by Wu and Chang (2011), and is added with the wave-sending boundary, radiation boundary and ability for simulating the moving boundary problem by this study. Two simulations are carried out for the model validation. First, regular waves propagating over a submerged breakwater are simulated. The results are compared with the experimental data, and the water particle trajectory is also discussed. The second one is waves generated by submerged landslide and the results are compared with other numerical solutions, such as BIEM and Boussinesq-type model. Fairly good agreements are observed in both of simulations. Finally, the present model is applied to calculate the subaerial landslide-induced waves. Subaerial landslide on three plane slopes of different angles, which are 6, 15 and 30 degrees, with the same constant water depth at the end of the slopes is studied. Specifically, the landslide-induced wave propagation and shoreline motions are examined. Furthermore, the effects of various sliding horizontal distances along the same slope on induced-wave are also discussed.

APA, Harvard, Vancouver, ISO, and other styles

47

Zhang, Jin E. "I. Run-up of ocean waves on beaches. II. Nonlinear waves in a fluid-filled elastic tube." Thesis, 1996. https://thesis.library.caltech.edu/56/1/Zhang_je_1996.pdf.

Full text

Abstract:

Part I This study considers the three-dimensional run-up of long waves on a horizontally uniform beach of vertically constant or variable slope which is connected to an open ocean of uniform depth. An inviscid linear long-wave theory is first applied to obtain the fundamental solution for a uniform train of sinusoidal waves obliquely incident upon a uniform beach of variable downward slope without wave breaking. The linearly superposable solutions provide a basis for subsequent comparative studies when the nonlinear and dispersive effects are taken into account, both separately and jointly, thus providing a comprehensive prospect of the extents of influences due to these physical effects. These comparative results seem to be new. By linear theory for waves at nearly grazing incidence, run-up is significant only for the waves in a set of eigenmodes being trapped within the beach at resonance with the exterior ocean waves. Fourier synthesis is employed to analyze a solitary wave and a train of cnoidal waves obliquely incident upon a sloping beach, with the nonlinear and dispersive effects neglected at this stage. Comparison is made between the present theory and the ray theory to ascertain a criterion of validity for the classical ray theory. The wave-induced longshore current is evaluated by finding the Stokes drift of the fluid particles carried by the momentum of the waves obliquely incident upon a sloping beach. Currents of significant velocities are produced by waves at incidence angles about 45° and by grazing waves trapped on the beach. Also explored are the effects of the variable downward slope and curvature of a uniform beach on three-dimensional run-up and reflection of long waves. When the nonlinear effects are taken into account, the exact governing equations for determining a moving inviscid waterline are introduced here based on the local Lagrangian coordinates. A special numerical scheme has been developed for efficient evaluation of these governing equations. The scheme is shown to have a very high accuracy by comparison with some exact solutions of the shallow water equations. The maximum run-up of a solitary wave predicted by the shallow water equations depends on the initial location of the solitary wave and is not unique in value because the wave becomes increasingly more steepened given longer time to travel in the absence of the dispersive effects; it is in general larger than that predicted by the linear long-wave theory. The farther the initial solitary wave of the KdV form is imposed from the beach, the larger the maximum run-up it will reach. The dispersive effects are also very important in two-dimensional run-ups in its role of keeping the nonlinear effects balanced at equilibrium, so that the run-ups predicted by the generalized Boussinesq model (Wu 1979) always yield unique values for run-up of a given initial solitary wave, regardless of its initial position. The result for the gB model is slightly larger than the wave run-up predicted by linear long-wave theory. The dispersive effects tend to reduce the wave run-up either for linear system or for nonlinear system. A three-dimensional process of wave run-up upon a vertical wall has also been studied. Part II This part is a study of nonlinear waves in a fluid-filled elastic tube, whose wall material satisfies the stress-strain law given by the kinetic theory of rubber. The results of this study have extended the scope of this subject, which has been limited to dealing with unidirectional solitary waves only (Olsen and Shapiro 1967), by establishing an exact theory for bidirectional solitons of arbitrary shape. This class of solitons has several remarkable characteristics. These solitons may have arbitrary shape and arbitrary polarity (upward or downward), and all propagate with the same phase velocity. The last feature of wave velocity renders the interactions impossible between unidirectional waves. However, the present new theory shows that bidirectional waves can have head-on collision through which our exact solution leaves each wave a specific phase shift as a permanent mark of the waves having made the nonlinear encounter. The system is at least tri-Hamiltonian and integrable. An iteration scheme has been developed to integrate the system. The system is distinguished by the fact that any local initial disturbance released from a state of rest will become two solitons traveling to the opposite direction, and shocks do not form if initial value is continuous.

APA, Harvard, Vancouver, ISO, and other styles

48

Ming-YangShih and 史名揚. "Simulation of Propagation and Run-up of Three Dimensional Landslide-induced Waves Using Meshless Method." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/ty74py.

Full text

Abstract:

碩士
國立成功大學
水利及海洋工程學系
104
This research is basically focused on 3-D water wave induced by landslide. Since it involves moving boundaries and large deformation of the computational domain, a 3-D numerical model is established with a meshless method and a fully nonlinear Lagrangian time marching scheme. Robust local polynomial collocation method which developed in the way that the collocations have to satisfy governing and boundary condition if it is the boundary point used in this study. This method is more efficient and accurate than the RBF-collocation method. Furthermore, due to its Lagrangian description of the flow motion, meshless method is effective in dealing with moving boundary problems such as free surface, landslide and wave-maker. Three dimensional experiments which regular waves pass an uneven bottom are chosen for simulation in order to validate the model. A fairly good agreement observed by comparing with the experiment data indicates that this model can successfully capture wave propagation phenomenon. The present numerical results which wave generated by a submerged landslide are compared with other numerical solutions using high-order Boussinesq-type model and experiment data in order to validate the ability of solving moving boundary problems in this meshless model. The results of simulation indicated that the present method is better than high-order Boussinesq-type model. Besides, the present model could predict the run-up height accurately. In this study, the edge waves caused by landslide-induced waves is disscussed and proved that the landslide-induced waves would cause edge waves by time-frequency analysis with wavelet transform.

APA, Harvard, Vancouver, ISO, and other styles

49

Chen, Chun-Jen, and 陳俊仁. "A Numerical Study on the Influence of a Breakwater to Flow Field and Run-up of Solitary Waves." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/13165638393351516715.

Full text

Abstract:

碩士
國立中興大學
土木工程學系所
101
This study investigated on the influence of a breakwater to flow field and run-up of solitary waves. A two-dimensional volume of fluid (VOF) type model called FLOW-3D, which is based on the Reynolds-Averaged Navier-Stokes (RANS) equations and the Renormalized Group k-Ɛ turbulence model, is validated by experimental data from Synolakis (1986). The results show that solitary waves passing through the breakwater, a jet-like flow injects the surface at the lee side. We also notice that the vortex generated at the top and lee-side of the breakwater. The vortex strength increase with the height of the breakwater. And we also observed at the place where vortex generated also induced the turbulent kinematic energy (TKE) and dissipation of turbulent kinematic energy (DTKE). The height of the breakwater also affect the run-up on the slope, breakwater higher the height, solitary wave run-up height is lower, the leading wave arrival time is slower. The forces impinging by the solitary wave on the breakwater is also affected by the breakwater height. The higher height, the greater force.

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Wave run-up'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles