Dissertations / Theses on the topic 'Sloping'
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LaCasce, Joseph H. 1964. "Baroclinic vortices over a sloping bottom." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/54422.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1996.Includes bibliographical references (p. 212-220).
by Joseph H. LaCasce, Jr.
Ph.D.
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Sipahi, Sabri Ozgur. "Calibration Of A Grate On Sloping Channel." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607889/index.pdf.
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In this study a setup is designed and constructed in the Hydromechanics Laboratory of Middle East Technical University in order to observe the flow through grate inlets under different flow and geometry conditions. The rate of interception of flow is determined over a rectangular channel through preliminary experiments run on the tilting flume. The performance of the new set setup has been examined and grate efficiency is obtained both in terms of longitudinal slope and the Froude number. The results which are obtained show that the setup can be used to conduct experiments to obtain a general expression for grate efficiency.
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Prinz, Joachim. "Why are wages upward sloping with tenure? /." München [u.a.] : Hampp, 2004. http://www.gbv.de/dms/zbw/389990906.pdf.
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Evans, Darren. "Swash on steep and gently-sloping beaches." Thesis, Loughborough University, 2004. https://dspace.lboro.ac.uk/2134/12664.
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In the last twenty years, the importance of sediment transport in the swash zone has been established. The disproportionately high sediment transport rates in this region make its inclusion in general nearshore models vital. As part of this U.K. Natural Environmental Research Council project (grant number: NERlA/S/1999/00144), high frequency (8 Hz) measurements were made of the water depth and vertical variations in suspended sediment concentration and water velocity, using state-of-the-art instrumentation. Further measurements included nearshore and offshore wave conditions, tidal elevations, wave run-up limits, groundwater variations, sediment grain size distributions, beach slopes and changes in morphology at time-scales from minutes to weeks. Fieldwork was carried out on a gently-sloping (tan p - 0.03; d50 ~ 0.27 mm) and steep beach (tan p - 0.09; d50 ~ 0.55 mm). Both experience similar wave climates which allows a direct comparison between hydrodynamics and sediment transport in the swash zone.
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Benthuysen, Jessica A. "Linear and nonlinear stratified spindown over sloping topography." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/59740.
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Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 199-205).
In a stratified rotating fluid, frictionally driven circulations couple with the buoyancy field over sloping topography. Analytical and numerical methods are used to quantify the impact of this coupling on the vertical circulation, spindown of geostrophic flows, and the formation of a shelfbreak jet. Over a stratified. slope, linear spindown of a geostrophic along-isobath flow induces cross-isobath Ekman flows. Ekman advection of buoyancy weakens the vertical circulation and slows spindown. Upslope (downslope) Ekman flows tend to inject (remove) potential vorticity into (from) the ocean. Momentum advection and nonlinear buoyancy advection are examined in setting asymmetries in the vertical circulation and the vertical relative vorticity field. During nonlinear homogeneous spindown over a flat bottom, momentum advection weakens Ekman pumping and strengthens Ekman suction, while cyclonic vorticity decays faster than anticyclonic vorticity. During nonlinear stratified spindown over a slope, nonlinear advection of buoyancy enhances the asymmetry in Ekman pumping and suction, whereas anticyclonic vorticity can decay faster than cyclonic vorticity outside of the boundary layers. During the adjustment of a spatially uniform geostrophic current over a shelfbreak, coupling between the Ekman flow and the buoyancy field generates Ekman pumping near the shelfbreak, which leads to the formation of a jet. Scalings are presented for the upwelling strength, the length scale over which it occurs, and the timescale for jet formation. The results are applied to the Middle Atlantic Bight shelfbreak.
by Jessica A. Benthuysen.
Ph.D.
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Bastin, Mark E. "Baroclinic waves in containers with sloping end walls." Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670276.
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Escurra, Jorge Jose. "Optimal Irrigation Management for Sloping Blocked-End Borders." DigitalCommons@USU, 2008. https://digitalcommons.usu.edu/etd/214.
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A robust mathematical model of one-dimensional flow for sloping, blocked-end border irrigation was developed using the four-point implicit method to solve the Saint-Venant equations, the volume-balance solution method, and the implementation of new algorithms to avoid numerical instability and solution divergence. The model has the capability of successfully simulating all surface irrigation phases in blocked-end borders for a range of inflow rates (0.01 - 0.05 m3/s per m), longitudinal slopes (up to 1.00%), and border lengths (100 - 500 m). To achieve numerical stability over the specified parameter ranges, the model was divided into three parts: (1) advance-phase simulation which uses the four-point implicit solution method of the Saint-Venant equations, with an algorithm that changes the spatial and temporal weighting, in addition to an algorithm that handles the water depth profile at the blocked-end downstream boundary upon completion of the advance phase; (2) simultaneous advance-recession-phase calculations using a hybrid algorithm to solve the governing equations; and (3) recession-phase simulation using the four-point implicit method until (and if) divergence occurs, then the volume-method is applied to complete the simulation. The three parts also involve the use of computational grid management algorithms and a parabolic equation which defines the Chezy coefficient as a function of water depth. The model incorporates the downhill simplex optimization method to determine the recommended inflow rate and irrigation cutoff time, maximizing a composite irrigation efficiency (water requirement efficiency and application efficiency). Different optimum values of inflow rate and irrigation cutoff time for a range of longitudinal slopes, border lengths, and soil types were generated. Most of the optimum values are for relatively high inflow rate and rapid cutoff time. In addition, exponential relations were developed, based on the simulation results, to determine the best irrigation time for maximization of the composite irrigation efficiency for specified, non-optimal inflow rates. The exponential relations are particularly useful in practice when it is not feasible to use the optimum inflow rate due to constraints at the water source, or because of irrigation scheduling issues.
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Wadi, Amer. "Flexible culverts in sloping terrain : Research advances and application." Licentiate thesis, KTH, Bro- och stålbyggnad, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-177903.
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Although the construction of flexible culverts involves simplicity in comparison to similar concrete structures, the complexity of the beneficial interaction between soil and steel materials requires good understanding for their composite action and performance. Current design methods have certain validity limitations with regard to applicable slopes above the structures. Given the short construction time of flexible culverts, there is an urge to explore the feasibility and the constructability of such as cost-effective structures in sloping terrain, where they may function as an avalanche protection structure for a given road, a culvert under a ski slope, or even as a protection canopy for tunnel entrances. This report compiles the efforts carried out toward gaining knowledge about the different factors that may affect the behaviour of flexible culverts in sloping environment. The report includes an extended summary of the investigation, which is mainly presented in two appended papers. The study involved numerical simulation of three case studies to investigate their performances with regard to soil loading and avalanche loads as well. The height of cover, surface slope intensity, slope stability, soil support conditions, and avalanche proximity, were studied and discussed. The study results allowed realizing the susceptibility of flexible culverts to low heights of soil cover when built in sloping terrain, which is reflected in the deformation response and the incremental change in sectional forces, especially the bending moments. It is also found that increasing the depth of soil cover may feasibly improve the structural performance under asymmetrical soil loading and avalanche loads, where it subsequently help in reducing the bending moments in the wall conduit. The presence of a flexible culvert may affect adversely the soil stability in sloping terrain and thus need to be addressed in design. Furthermore, the flexural response of a flexible culvert is directly influenced by the soil support configuration at the downhill side of the structure. In addition, the report also attempts to highlight some general guidelines about the design aspects of flexible culverts in sloping terrain, and seeks to reflect some of the findings on the design methodology for flexible culverts used in Sweden.QC 20151130
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Mzava, Philip G. "Groundwater elevation estimation model in the sloping Ogallala aquifer." Thesis, Kansas State University, 2010. http://hdl.handle.net/2097/4378.
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Master of ScienceDepartment of Civil Engineering
David R. Steward
A one-dimensional model was developed to study the flow of groundwater in the sloping Ogallala Aquifer at a steady state during predevelopment condition. The sloping base was approximated using a stepping base model. GIS applications were applied during data collection and preparation, and later during interpretation of model results. Analytical and numerical methods were employed in the development of this model which was used to try to understand long-term water balance in the study region. The conservation of mass was achieved by balancing groundwater input, output, and storage; this led to understanding the interactions of groundwater and surface water in the predevelopment conditions. The study resulted in identification of where natural discharge from groundwater to surface water occurred, and the quantity of these flows was obtained. The Ogallala Aquifer is thick in the south western part of Kansas, this region had an average saturated thickness of 100m during predevelopment conditions. The model found that groundwater flowed at a discharge per width of approximately 17 m[superscript]2/d in this region. The aquifer thickness tends to gradually decrease from west to east and from south to north. The northern part had an average saturated thickness of 40m during predevelopment conditions; the model found that groundwater flowed at a discharge per width of approximately 3 m[superscript]2/d in this region. It was also found that groundwater leaves the Ogallala Aquifer on the eastern side with discharge per width between 0-3 m[superscript]2/d. The discharge from groundwater to surface water was summed over contributing areas to river basins. The discharge to streams necessary to satisfy long-term conservation of mass computed by the model showed that Cimarron River has total baseflow of about 5.5 m[superscript]3/s; this was found to be almost 100% of the total streamflow recorded during predevelopment conditions. The Arkansas River was found to have total baseflow of about 0.97 m[superscript]3/s, which is approximately 14.3% of the total streamflow recorded during predevelopment conditions. The Smoky Hill River was found to have total baseflow of about 1.7 m[superscript]3/s, which is approximately 73.9% of the total streamflow recorded during predevelopment conditions. The Solomon River was found to have total baseflow of about 0.95 m[superscript]3/s, which is approximately 41.1% of the total streamflow recorded during predevelopment conditions. The Saline River was found to have total baseflow of about 0.25 m[superscript]3/s, which is approximately 62.5% of the total streamflow recorded during predevelopment conditions. The Republican and Pawnee River was found to have total baseflow of about 0.38 m[superscript]3/s and 0.22 m[superscript]3/s, which is approximately 18.5% and 12.6% of the total streamflow in the predevelopment conditions respectively. The model was found to be always within -16 to +12 meters between observed values and the model results, with an average value of 0.15m and a root mean square error of 1.98m. Results from this study can be used to advance this study to the next level by making a transient model that could be used as a predictive tool for groundwater response to water use in the study region.
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Boegman, Leon. "The degeneration of internal waves in lakes with sloping topography." University of Western Australia. Centre for Water Research, 2004. http://theses.library.uwa.edu.au/adt-WU2005.0043.
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[Truncated abstract] Observations are presented from Lake Biwa (Japan) and Lake Kinneret (Israel) showing the ubiquitous and often periodic nature of high-frequency internal waves in large stratified lakes. In both lakes, high-frequency wave events were observed within two distinct categories: (1) Vertical mode one solitary waves with wavelength ˜100-500 m and frequency near 103 Hz and (2) sinusoidal vertical mode one waves with wavelength ˜5-30 m and frequency just below the local maximum buoyancy frequency near 102 Hz. The sinusoidal waves were associated with shear instability and were shown to dissipate their energy sporadically within the lake interior. Conversely, the solitary waves were found to be capable of propagating to the lake perimeter where they may break upon sloping topography, each releasing ˜1% of the total basin-scale internal wave energy to the benthic boundary layer.
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Skrobic, Karina, and Josefine Bergström. "Static analysis of soil-steel composite bridges in sloping terrain." Thesis, KTH, Bro- och stålbyggnad, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-164298.
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Soil-steel composite bridges are for many reasons very favorable bridges to build. Up to a certain span length they are economical, practical to transport and simple and quick to build. Especially in remote places, with unfavorable sloping terrain, this can be of great interest when the transport of material can be difficult and costly. The swedish manual for design of soil steel composite bridges was presented by Lars Pettersson and Håkan Sundquist in the year 2000. It is today used in Sweden and other neighboring countries as the main manual for the design of soil-steel composite bridges. The design manual is however only valid for longitudinal slopes up to 10%, which is low in comparison to natural sloping hillsides. The purpose of this thesis is to study the structural behavior of soil steel composite bridges in sloping terrain, with the use of the finite element software PLAXIS 2D. Two case studies of one low arch culvert bridge and one pipe arch culvert are studied and later modeled in PLAXIS. The two case studies does not have sloping terrain, but are used to assure that the FEM-models behaves correctly during the backfilling process in PLAXIS. The analysis studies the change in sectional forces in the bridges during an increase inslope above the structures. The values from the FEM-models are compared to field measurements from the case studies, as well as to values calculated in accordance to the swedish design manual. This is done to see how well the different approaches compare to each other, and, since the design manual does not consider slopes exceeding 10%, it is interesting to investigate if the SDM-calculated values still appear valid for slopes larger than 10%. In addition to sectional forces, the slope stability of the FEM-models is also evaluated and compared to analytical values calculated using the ordinary method of slices. This slope stability study focuses on if the bridges affect the slope stability safety factor. The thesis also investigates if these bridges are more sensitive to increasing slopes from a slope stability or sectional forces point of view. I.e if the slope inclination magnitude will be determined based on the sectional forces in the structure or the slope stability of the soil surrounding the structure. The criteria that are researched to come to this conclusion are for example the slope stability safety factor, or the possible yielding of the culvert wall due to too large sectional forces in the structure. The results show that for low cover depths, the slope stability safety factor decreases slightly when a structure is introduced to the slope. For larger cover depths, read 3 meters or more, the slope stability seems unaffectedby the structure. The results also shows that the sectional forces in the structures compares well to both measured and calculated values for slope inclinations up to 30% for rather small cover depths, i.e 1 meter. For slopes larger than 30% the sectional forces grows and no longer reflect the measured and calculated values. However, since only two case studies are performed, these conclusions might not be valid for different profile shapes. Additionally there are indications that the low arch bridge is more sensitive to slopes than the pipearch culvert.Rörbroar, eller “soil-steel composite bridges”, är av många anledningar fördelaktiga att bygga. Upp till en viss spännvidd är de ekonomiska, praktiska att transportera samt enkla och snabba att konstruera. Särskilt vid vissa svåråtkomliga platser, med ofördelaktigt sluttande terräng, kan det vara av stort intresse när materialtransport annars kan vara både komplicerat och kostsamt. Den svenska manualen för dimensionering av rörbroar presenterades av Lars Pettersson och Håkan Sundquiståret 2000. Manualen används idag i Sverige samt angränsande länder som den huvudsakliga dimensioneringsmanualen för rörbroar. Dock är den svenska manualen enbart giltig för lutningar upp till 10%, vilket ären låg lutning i jämförese med många naturliga sluttningar. Syftet för detta arbete är att studera det statiska beteendet hos kringfyllda rörbroar i lutande terräng,med hjälp av det finita element programmet PLAXIS 2D. Två fallstudier av dels en låg bågbro, dels en sluten kulvertbro, studeras och modelleras senare i PLAXIS. De två fallstudierna har inte sluttande terräng, men används för att säkerställa att FEM-modellerna beter sig korrekt under återfyllnadsfasen I PLAXIS. Analysen studerar förändringen av tvärsnittskrafter i broarna när sluttningen de belastas av ökar. Värdena från FEM-modellerna jämförs mot mätdata från fallstudierna, samt mot värden beräknade enligt den svenska manualen. Detta utförs för att se hur väl de olika metoderna överensstämmer med varandra, och, eftersom dimensioneringsmanualen inte tar hänsyn till lutningar överstigande 10%, är det intressant att se om deSDM-beräknade värdena fortfarande gäller för lutningar större än 10%. Utöver tvärsnittskrafter utvärderas släntstabiliteten hos FEM-modellerna, och dessa resultat jämförs sen mot analytiska värden beräknade enligt lamellmetoden, eller “the ordinary method of slices”. Släntstabilitetsstudien fokuserar på hur broarna påverkar säkerhetsfaktorn för släntstabilitet. Avhandlingen undersöker även om dessa broar är mer känsliga för ökande lutningar från en släntstabilitets- eller tvärsnittskrafts-synvinkel, dvs. om lutningens största storlek kommer att avgöras baserat på de tvärsnittskrafter som uppstår i konstruktionen eller på släntstabiliteten i marken runt konstruktionen. För att bilda oss en uppfattning om detta jämförs exempelvis säkerhetsfaktorn för släntabilitet mot ett eventuellt brott i stålprofilen orsakat av för stora tvärsnittskrafter i konstruktionen. Resultaten visar att säkerhetsfaktorn för släntstabilitet, vid liten överfyllnadshöjd över hjässan, minskar något när en bro byggs i en sluttning. För större överfyllnadshöjder, läs 3 meter och högre, verkar släntstabiliteten vara oförändrad vid introducering av en bro. Resultaten visar även att tvärsnittskrafterna i konstruktionerna överensstämmer bra både mot mätdata samt beräknade värden, för lutningar upp till 30% och små överfyllnadshöjder på exampelvis 1 meter. För lutningar större än 30% växer tvärsnittskrafterna och är inte längre jämförbara mot varken mätdata eller beräknade värden. Dock bör det tilläggas att eftersom endast två fall har studerats utförs så behöver dessa slutsatser inte gälla för andra profiltyper. Utöver detta finns indikationer på att den låga rörbron är mer känslig för en ökning i släntlutning i jämförelse mot denandra bron när det gäller tvärsnittskrafter.
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Oikonomou, Emmanouil Konstantiou. "Stationary phase internal waves generated by flow along sloping topography." Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242690.
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Ozturk, Hayrullah Ugras. "Discharge Predictions Using Ann In Sloping Rectangular Channels With Free Overfall." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606706/index.pdf.
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In recent years, artificial neural networks (ANNs) have been applied to estimate in many areas of hydrology and hydraulic engineering. In this thesis, multilayered feedforward backpropagation algorithm was used to establish for the prediction of unit discharge q (m3/s/m) in a rectangular free overfall. Researchers&rsquoexperimental data were used to train and validate the network with high reliability. First, an appropriate ANN model has been established by considering determination of hidden layer and node numbers related to training function and training epoch number. Then by applying sensitivity analysis, parameters involved in and their effectiveness relatively has been determined in the phenomenon. In the scope of the thesis, there are two case studies. In the first case study, ANN models reliability has been investigated according to the training data clustered and the results are given by comparing to regression analysis. In the second case, ANN models&rsquo
ability in establishing relations with different data clusters is investigated and effectiveness of ANN is scrutinized.
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Salem, Hicham J. "Nonlinear eleastic modeling of pipeline in sloping clay under high Ko." Thesis, University of Ottawa (Canada), 1999. http://hdl.handle.net/10393/8550.
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Numerous cases of pipeline failures are documented every year, triggering new problems for research and the need for re-examination of already established design guidelines and standards. The problem of soil/pipeline interaction has been thoroughly researched over the years; however, further investigation is required in some areas. This thesis presents an investigation. using numerical modeling to simulate the installation of a steel pipeline in overconsolidated clay. Some factors related to the site geometry (sloping ground) and construction methods (fill compaction), as well as the stiffness of the pipeline section, are also investigated. This study shows that the reaction of the soil mass to the trench excavation continued for as long as four years after backfilling. In addition, the following conclusions can be drawn from the results presented in this thesis: (1) When the pipeline is installed in a trench, at the base of a v-shaped depression, a higher total stress acts at the base and crown of the pipeline with level ground and smaller ground slopes causing more deformation in the pipeline section than with steep ground slopes. (2) A static, surcharge-type compaction for a reasonable duration is found to reduce damaging stresses at the base and crown of the pipeline, during and after surcharge loading. (3) A less rigid pipeline section would carry less of the weight of overlying fill material and will cause more of the load to be carried by the fill material on either side of the pipeline. This results in higher lateral pressure (in the pipeline section and slower dissipation of pore water pressure around the pipeline.
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White, Martin George. "The temperature and current structure on the sloping benthic boundary layer." Thesis, University of Southampton, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315088.
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Marshall, Samuel David. "Sloping convection : an experimental investigation in a baroclinic annulus with topography." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:ca9cfaf5-49e8-4e30-b93a-65c27d1c8a15.
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This thesis documents a collection of experimental investigations in which a differentially-heated annulus was used to investigate the effects of topography on the atmospheric and oceanic circulation. To this end a number of experiments were devised, each using a different topographic base to study a different aspect of the impact of topography, motivated by the most notable outstanding questions found in a review of the literature, namely exploring the effects of topographic resonance, blocking via partial barriers, and azimuthally differential-heating via thermal topography. First of all, whilst employing sinusoidal wavenumber-3 topography to extend the experimental parameter space of a similar study, namely Read and Risch (2011), a new regime within a region of structural vacillation was encountered. Denoted as the ‘stationary-transition’ regime, it featured periodic oscillations between a dominant stationary wavenumber-3 flow and axisymmetric or chaotic flow. An investigation into topographic resonance followed, keeping the wavenumber-3 base, but with a sloped lid to add a beta effect to the annulus. This acted to increase the occurrence of stationary waves, along with the ‘stationary-transition’ regime, which was discovered to be a near-resonant region where nonlinear topographic resonant instability led to a 23 to 42 ‘day’ oscillatory structure. The base was then replaced with an isolated ridge, forming a partial barrier to study the difference between blocked and unblocked flow. The topography was found to impact the circulation at a level much higher than its own peak, causing a unique flow structure when the drifting flow and the topography interacted in the form of an ‘interference’ regime at low Taylor Numbers, as well as forming an erratic ‘irregular’ regime at higher Taylor Numbers. Lastly, this isolated ridge was replaced by flat heating elements covering the same azimuthal extent, in order to observe whether thermal topography could be comparable to mechanical topography. These azimuthally-varying heating experiments produced much the same results as the partial barriers study, despite the lack of a physical peak or bottom-trapped waves, suggesting that blocking is independent of these activities. Evidence of resonant wave-triads was noted in all experiments, though the component wavenumbers of the wave-triads and their impact on the flow was found to depend on the topography in question.
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Haigh, Stuart Kenneth. "Effects of earthquake-induced liquefaction on pile foundations in sloping ground." Thesis, University of Cambridge, 2002. https://www.repository.cam.ac.uk/handle/1810/284009.
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This thesis details the results of an investigation into the behaviour of slopes of liquefiable sand under earthquake loading and the influence of these laterally spreading slopes on inclusions such as pile foundations passing through them. A study of the behaviour of these slopes has been carried out using the techniques of dynamic centrifuge modelling. Eight tests were carried out on laterally spreading slopes and a further five on slopes containing instrumented pile foundations. Each model was subjected to a sinusoidal input motion using a Stored Angular Momentum earthquake actuator, causing liquefaction of the sand and lateral spreading of the slope. Data from instruments measuring acceleration, fluid pressure, total stress and bending moment were logged during the earthquake and analysed to reveal information relating to the performance of these slopes during earthquakes. The experiments highlighted the importance of the dilation of liquefied soil to the behaviour of liquefiable slopes. Slope movements were limited by dilation during each cycle of the earthquake which prevented significant soil flow velocities from building up and large pressures were applied to piles from the liquefied soil owing to dilation of soil close to the pile foundation. It was shown that these large lateral forces were not wholly transmitted into bending moments due to the dynamic response of the piles, but this could be the cause of significant pile damage in other situations. It was also seen that present design methods are non-conservative for both the induced bending moments and the applied lateral loads. Further research is needed to develop better design guidance for this situation. The data from these experiments was compared with the results of a number of numerical models constructed during this work in order to simplify the prediction of the behaviour of these slopes. The displacements of the slopes were compared with those predicted using a Newmarkian sliding block approach modified to include the effects of excess pore pressures. This was shown to give reasonable agreement with centrifuge data, though it requires input of a measured or predicted time-history of excess pore pressure to calculate threshold accelerations.
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Fırat, Can Ersen. "Effect of roughness on flow measurements in sloping rectangular channels with overfall." Ankara : METU, 2004. http://etd.lib.metu.edu.tr/upload/12604775/index.pdf.
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Firat, Can Ersen. "Effect Of Roughness On Flow Measurements In Sloping Rectangular Channels With Free Overfall." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12604775/index.pdf.
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The characteristics of the subcritical, critical and supercritical flows at the rectangular free overfall were studied experimentally to obtain a relation between the brink depth and the flow rate. A series of experiments were conducted in a tilting flume with wide range of flow rate and two bed roughness in order to find the relationship between the brink depth, normal depth, channel bed slope and bed roughnesses. An equation was proposed to calculate the flow rate if only the brink depth, roughness, and channel bed slope are known. An alternate iterative solution was offered to calculate discharges if the brink depth and uniform flow depth are known.
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Salem, Hicham J. "Nonlinear eleastic modeling of pipeline in sloping clay under high K[subscript]o." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0004/MQ45248.pdf.
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McPhee, Erika E. "Internal-wave mixing along sloping boundaries : a mechanism for generating intermediate nepheloid layers /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/10972.
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Holt, Jason Tempest. "Topographic influences on Kelvin-Helmholtz instability." Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295515.
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Baryla, Andrew John. "Laboratory measurements of wave-induced near-bed velocity over a sloping natural sand beach." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ35051.pdf.
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El-Solh, Safinaz. "SPH Modeling of Solitary Waves and Resulting Hydrodynamic Forces on Vertical and Sloping Walls." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/23778.
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Currently, the accurate prediction of the impact of an extreme wave on infrastructure located near shore is difficult to assess. There is a lack of established methods to accurately quantify these impacts. Extreme waves, such as tsunamis generate, through breaking, extremely powerful hydraulic bores that impact and significantly damage coastal structures and buildings located close to the shoreline. The damage induced by such hydraulic bores is often due to structural failure. Examples of devastating coastal disasters are the 2004 Indian Ocean Tsunami, 2005 Hurricane Katrina and most recently, the 2011 Tohoku Japan Tsunami. As a result, more advanced research is needed to estimate the magnitude of forces exerted on structures by such bores.
This research presents results of a numerical model based on the Smoothed Particle Hydrodynamics (SPH) method which is used to simulate the impact of extreme hydrodynamic forces on shore protection walls. Typically, fluids are modeled numerically based on a Lagrangian approach, an Eulerian approach or a combination of the two. Many of the common problems that arise from using more traditional techniques can be avoided through the use of SPH-based models. Such challenges include the model computational efficiency in terms of complexity of implementation. The SPH method allows water particles to be individually modeled, each with their own characteristics, which then accurately depicts the behavior and properties of the flow field. An open source code, known as SPHysics, was used to run the simulations presented in this thesis. Several cases analysed consist of hydraulic bores impacting a flat vertical wall as well as a sloping seawall. The analysis includes comparisons of the numerical results with published experimental data. The model is shown to accurately reproduce the formation of solitary waves as well as their propagation and breaking. The impacting bore profiles as well as the resulting pressures are also efficiently simulated using the model.
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Lin, Hsing-Hua, and 劉興華. "Braced Cuts on Sloping Ground." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/04747996512772293482.
Full textAbstract:
碩士國立交通大學
土木工程系
89
For analysis of braced cuts on sloping ground, this research focus on three factors of stability and variable of deep excavation such as lateral retaining wall deformation, the maximum amount of ground settlement (δh,max ), and the strut load. To combine the monitoring data and RIDO formula produce the back analysis. Simultaneously, the differences between two factors derive from the analysis of the deep ground excavation. It looks forward to find out the soil parameter of braced cuts on sloping ground or other revisional methods. According to wall deformation from the result of this research, the deformation curve of braced cuts on sloping ground tends to cantilever style. Under the result from the back analysis of RIDO formula, three significant parameters are able to influence the result of formula calculation. They are the stiffness of retaining wall (EI:0.6~0.7); the angle of friction between soil and retaining wall (δ/φ:1/3~1/2); the coefficient of sub-grade reaction (Kh:100~175 N). The result of back analysis is closer to the value of monitoring. KEY WORDS：deep excavation, retaining wall deformation, ground settlement, strut load, RIDO program.
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Tsai, Yih-Chung, and 蔡毅中. "Earth Prerssure At-Rest with Sloping Backfill." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/36162676357024793077.
Full textAbstract:
碩士國立交通大學
土木工程學系
84
Earth Pressure At-Rest with Sloping BackfillStudent: Yi-Chung Tsai Advisor: Dr. Yung-Show FangInstitute of Civil EngineeringNational Chiao Tung UniversityABSTRACTThis paper investigates the earth pressure at-rest against a non- yielding wall with sloping backfill. A unique model retaining wall syste m at the National Chiao Tung University is used for this study. Air-dry Ottawa silica sand (ASTM C-109) is used as backfill for the experiments. A Wedge equ ilibrium method is proposed to estimate the earth pressure at-rest against a n on- yielding wall with horizontal backfill. Based on the test results, the foll owing conclusions can be drawn.1. The distribution of the earth pressure at-re st against the wall with horizontal backfill is nearly linear, and in fairly g ood agreement with the solution calculated with the wedge equilibrium method. The point of application of total thrust is located about 0.34 to 0.36H above the wall base.2. The measured pressure distributions against the wall are in f airly good agreement with elastic solutions for positive backfill inclinations . However the pressure measured are significantly greater than the elastic sol utions for negative i angles.3. At-rest earth pressure coefficient {embed Equa tion.2 |} increases with increasing slope angle {embed Equation.2 |}of the bac kfill. The experimental {embed Equation.2 |} values are in good agreement with elastic solutions for positive backfill inclinations. The elastic solution te nds to underestimate the coefficient {embed Equation.2 |} for backfills with n egative sloping angles.4. The application of superposition of stresses may be misleading on a mass with discrete particles, especially when tensile stress i s involve.
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施佳利. "Characteristics of Breaking Waves on Sloping Beaches." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/69947817759651281423.
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Hsu, Hung-Chu, and 許弘莒. "Nonlinear Analysis of Progressive Waveson Sloping Bottoms." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/83528557118257096009.
Full textAbstract:
博士國立成功大學
水利及海洋工程學系碩博士班
93
For wave propagating on sloping bottoms, this study extends the model of Chen(2003Ⅰ、Ⅱ) to analyze the influences of the wave steepness and the bottom slope. Based on the principle of wave motion with nonlinear free-surface boundary conditions, rigid bottom boundary condition and the conservation of time-averaged mass flux, the nonlinear solution for the velocity potential is derived as a two-parameter function of the nonlinear ordering parameter ε and the bottom slope α perturbed to the fourth order (εmαn,m+n=4) in the Eulerian coordinate system. The solutions up to εiαj(i+j=3) order are exactly the same as those of Chen (2003Ⅱ). For the higher order solutions obtained by this study, it is found that bottom slope α is related to the changes of wave elevations and wave profile in the ε1α3 order solution . The effect of bottom appears in the quantity of α3∫x x0e3dx´, which has not yet been obtained by Chen (2003Ⅱ). The velocity potential to ε2α2 order includes a second harmonic and a time–independent potential, all affected by the second-order bottom slope effect. The corresponding free surface elevation contains a new mean sea-level set-down α2η2,2,0 term due to the slope effect and a second harmonic η2,2,2. The velocity potential to the ε3α1 order includes a third harmonic term that depends on the bottom slope. Finally the velocity potential to ε4α0 order includes an oscillatory term, which is the form of potential of the Stokes fourth harmonic, and the time-independent potential. To check the validity of the nonlinear analytical solution, it is shown analytically that, in the limit of deep water or constant depth, the nonlinear solution approaches the well known classical Stokes fourth-order solution of progressive waves. The transformation between Eulerian and Lagrangian coordinates is used to calculate the water particle motion up to second order. Up to now, it is known that the Eulerian solution of Stokes wave up to the third order cannot be transformed into the corresponding Lagrangian solution. It still need to make further research. The Lagrangian velocity in this paper is calculated only to the order of ε2α1. The displacement of the water particle X and Y to the ε2α1-order approximation can thus be written by integration. These enable the description of the features of wave shoaling in the direction of wave propagation from deep to shallow water and the deformation of a wave profile, particularly, the successive process of the wave plunging or spilling on a beach near the breaking point. From theoretical analysis, it is apparent that the asymmetry parameter is the function of the bottom slope and the square of incident wave steepnessλ0a0. The absolute value of the asymmetry parameter |s| increases with decreasing water depth for a given slope. In addition, for a given wave steepness, |s| also increases as the bottom slope α increases. From theoretical analysis, the mass transport velocity on the sloping bottom is proportional to the bottom slope and the incident wave steepness. In the limiting case where the water depth is constant and finite, the Stokes’ drift is reduced to that derived by Longuet-Higgins (1953). This study also obtained the wave-induced set-down in the shoaling zone, correct to the ε2α2 order, is a function of both the square of the bottom slope and the square of the incident wave steepness λ0a0. Comparing the theoretical set-down with the experimental data of Saville (1961), the present theory shows good agreement with the experimental results while the L-H/S theory tends to underestimate the set-down. Thus, it can be concluded that this averaged surface depression depends on the slope of the bed, and this dependence increases significantly for steep slopes. The present theoretical formulae developed will be applicable for cases of arbitrary bottom slopes. By examining the ratio of the high-order term to the low-order term, which must be less than 1 in order for the series for ψ, the region of validity of the present study can be obtained.
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Po, Lai Tung, and 賴東柏. "Breaker Index of Irregular Waves on Sloping Beaches." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/59411083143312874879.
Full textAbstract:
碩士逢甲大學
土木及水利工程研究所
87
As a deep water wave propagates into shallow water, the wave steepness increases as water depth decreases, finally the wave breaks as the result of the wave loses it''s shape. In fact, the waves in the realistic ocean are irregular, so this study is focuses on irregular waves breaking on sloping beaches.As a result,we can find that the relation between the breaking height and breaking depth is affected by the deep water wave steepness and the bottom slope with each other. As the deep water wave steepness increases, the breaking index and the ratio of the breaking height-death are decrease, and they are increases as the bottom slope become steeper. Finally we can get some relations by regressed.
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FU-TUNG, CHANG, and 張富東. "The surface-waves propagating on a sloping beach." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/81714112960837851078.
Full textAbstract:
碩士國立中山大學
海洋環境及工程學系
87
By linearizing the problem of the surface-waves propagating on a gentle sloping beach in two dimension, this paper has developed by a suitable perturbation expansion in the bottom slope to any order and the analytical solution has been derived to third order . Furthermore, the Eulerian form is transformed to the Lagrangian form by making use of a transform function to describe the solution. The Lagrangian form can be computerized by the numerical quadrate procedure with a personal computer program of continence. This program can easily calculate the result for the diverse surface-waves propagating on the any gentle sloping beach. When the momentary serial data of the undulate waves was calculated, it could combine into the dynamic three-dimension graph of full-time evolution by the skills of the multimedia. Finally, performs a practical experiment to inspect the theoretical and numerical result and researches the agreements between the reality and the solution. Comparing the experimental data with the solutions for the different wave steepness of the deep water on the three kinds sloping beach (1/5,1/10,1/20), the wave height proportion value is between 0.892 to 1.177,the wavelength proportion value between 0.953 to 1.163 and the wave steepness proportion value between 0.901 to 1.087. Over 95% the experiment data and solutions, the errors between them are less than 10%. Hereinbefore, These evidences can prove out the theoretical solution and numerical result, which can suffice the reality.
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Lin, Wen-Lan, and 林文嵐. "Study of Wave Overtopping on Step Sloping Dike." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/zaj45v.
Full textAbstract:
碩士逢甲大學
土木及水利工程所
91
The experiment on influence of step dike to wave overtopping in various incident wave conditions was completed in this study. The comparison of wave overtopping rate on smooth dike by experiment to the results of the analysis by Van der Meer(1998) was finished at first. We can see its tendency was quite similar.But, in the step dike condition, when the dike slope become milder then the wave overtopping rate was decreased rapidly. At the second, the profile of wave runup that proposed by Cross(1972) was quote to used for the calculation of the wave overtopping rate in this study. In smooth dike surface condition, the result of analysis shows when the dike slope becomes milder then the correlation between the theoretical wave overtopping rate and the relative crest height( ) was coincide to the results that obtained by the experiment. However, in step dike condition, the decrease down of the wave overtopping rate becomes obvious when the relative crest height increased. In addition, by apply the same wave runup profile to do the dimensionless analysis for compute the dimensionless wave overtopping rate then to compare with the results from the experiment. Results shows the relationship between the theoretical wave overtopping rate and the experiment’s to the relative crest height has the same tendency either in smooth dike or step dike too.
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Swales, Dustin J. Young George S. "Shear driven gravity waves on a sloping front." 2009. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-3764/index.html.
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Yang, Kuei-Sen, and 楊貴森. "An evolution of breaking wave on sloping bottoms." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/86586720942552608707.
Full textAbstract:
博士國立中山大學
海洋環境及工程學系研究所
101
This thesis discusses the plunging or spilling wave breaking profiles for the progressive water waves propagating on gentle sloping bottoms. Due to the shoaling effect, the wave height will increase and the wave length will shorten as well as the asymmetry of wave profile will appear. As the wave continues to move to the shore, the wave velocity will decrease and the wave profile will be pushed to steep in the vertical direction. As the slope of wave profile approaches to large, the horizontal velocity of the water particle at the wave crest will larger than wave phase velocity and the wave breaking will occur and move forward in the free-body projectile motion.The theoretical solution derived by Chen at al. (2005) for the progressive waves propagating on sloping bottoms, the wave breaking criteria and the equation of the particle projectile motion after the wave breaking are included to discuss the continuous variations of wave profile for the plunging or spilling breaking waves. A laboratory experiment is conducted in order to validate the theoretical wave breaking profile on sloping bottoms with measures. Wave breaking profiles can be verified obtained by the theoretical solution and experimental measurements. The experimental measurements were carried out in a glass-walled wave tank, 21m×0.7m×0.5m, in Tainan Hydraulics Laboratory , National Cheng Kung University. A High-Speed camera was set up in front of the glass-wall at the different breaking point locations depending on the initial wave conditions. This method allows to successively capturing the wave breaking profiles. Images were captured by a High-Speed camera (MS55k2, Canadian Photonic Labs Inc.), which has a 1280*1080 pixel resolution and maximum framing rate 1020 frames per second (fps). A transparent acrylic-plastic sheet (0.9 m×0.625m) was calibrated at 1-mm intervals in 5 mm×5 mm grids. Its function is a virtual grid in the picture. The experiments were conducted at two different bottom slope ( ,1/20) and two different water depth (d=37.6m, 40.0cm) and various wave periods from =0.8sec~3.0sec). The range of incident wave heights were from 4 cm~8cm. According to the comparison results between the theoretical solution and experimental data, the wave profile evolution of plunging or spilling breaking wave on sloping bottoms can be described. Meanwhile, it is also proved that the instantaneous wave profiles after the breaking wave is good agreement. The duration of the overturning wave is less known by the analytical solution. The present theory can well describe the wave shoaling, as well as the occurrence of breaking wave and wave overturning, similar to the plunging jet in the breaking water waves over sloping bottom. Comparing the sequence of computed wave breaking profiles with snapshots of breaking wave behavior over a sloping bottom captured by the high-speed camera shows a good agreement of the theoretical wave breaking profile with laboratory measurements. The breaker jet creating a forward moving jet is well observed in the present theoretical results. This indicates that the theoretical solution is accurate for modeling such post-breaking waves. Keyword：free-body,projectile,waves breaking,plunging,spilling
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Huang, Yu-Han, and 黃鈺涵. "An experimental study of ponding infiltration on sloping surface." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/c376uj.
Full textAbstract:
碩士國立中央大學
土木工程研究所
96
The infiltration processes across both the horizontal plane and the sloping surface under ponding condition are experimentally examined in this study. The Green-Ampt equation proposed by Chen and Young(2006) is compared with experimental data.. In one-dimensional case, infiltration along the normal direction is mainly controlled by capillary forces. A Hele-Shaw model was established, which satisfies the condition of homogeneous and isotropic for the Green-Ampt assumption. The saturated wetting front depth can be measured with the Hele-Shaw model approach. On the other hand, a sand-box experiment was established to observe real infiltration cases. According to the experimental data, the Green-Ampt model is only applicable at the beginning stage. The deviations between Green-Ampt model and experimental results become obvious afterwards due to gravitational effect. A dimensionless parameter define the time factor between the influence of capillary force and the gravity is proposed in this study.
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Lai, Cheng-Che, and 賴正哲. "Experimental study of sand bar disposition on sloping bottom." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/53916033976906583169.
Full textAbstract:
碩士國立成功大學
水利及海洋工程學系碩博士班
94
The objective of this thesis is to investigate the evolutions of sand bar under different wave breaking locations. The experiments are conducted in a glass-side walled wave flume. A series of experiments with different wave conditions and installations of bars are conducted on bottom slopes of 1/20 and 1/60. The total dimensionless accumulative transport rate is divided into onshore and offshore transport rate to determine the proper damping position and installation of sand bar. The results show that the onshore transport rate is affected significantly by Shields parameter. The onshore transport rate is larger as waves break on the bar than as waves break behind the bar. It is found that over 50% volume of sand bar will be transported onshore as wave break on the bar. Additionally, the offshore transport rate is found to be relative to the bottom slope. As the slope is milder, the offshore transport rate is lower. Finally, it is concluded that better benefit can be obtained in beach nourishment under 0.1 hc/Bc<0.21.
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Chen, Li, and 陳立. "Crictal flow in compound channel with sloping flood-plains." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/64334408576529748463.
Full textAbstract:
碩士國立成功大學
水利及海洋工程學系
89
There are discontinuous interfaces in compound channels that have a horizontal flood plain especially at just overbank stages, if we consider that compound channel had sloping floodplains, the discontinuity would be disappeared. For discuss critical depth occurs on compound channels, this paper established a dimensionless parameter Φ,equals to Qc/Qcmc. And observed the actually critical condition on control section by experiment. The experiment showed that flow passed thru the control section was three-dimension, by using energy coefficient α ,could take this in one-dimension, after this procedure, the Fr. No. and Φ could describe the critical condition at the compound channel with sloping flood-plain. If the sloping angle is very small, it could also describe the critical condition at the compound channel with flat flood-plain. Because Φ was the ratio of any critical Q and main channel’s bracketed Q, and if any compound channel could establish the relationship of Φ to water depth, we can estimate the critical water depth at particular Q, or rated at Q by this way.
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Chen, Yu-Yin, and 陳宥尹. "Gravity currents from instantaneous sources propagating on sloping boundaries." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/68751731260783834546.
Full textAbstract:
碩士淡江大學
水資源及環境工程學系碩士班
100
Gravity currents, also known as density currents, are buoyancy-driven flows generated by a density difference. The density difference can be due to a temperature differential, dissolved or suspended materials, e.g. salt and sediments. In recent years, the research in gravity currents has drawn significant attention concerning the operation and sedimentation management of reservoirs in Taiwan. Understanding the characteristics of gravity currents on sloping boundaries can effectively improve the operation and sedimentation removal in reservoirs. At present, the research of gravity currents on sloping boundaries can be divided into two categories based on the inflow condition, i.e. continuous buoyancy inflow and instantaneous (discontinuous) buoyancy release. Even in the continuous inflow case, occasionally the gravity currents generated can be similar to the discontinuous case. Our focus here is on discontinuous gravity currents on sloping boundaries and to study the impact of the slope angle on the characteristics of gravity currents, including the front velocity, the spatial growth rate of the head, entrainment, detrainment, and comparison against the low-dimensional thermal theory. The broadly used thermal theory was developed by Beghin, Hopfinger, and Britter (1981 J. Fluid Mech.). In this study, we found that as the angle increases, the length, height, maximum concentration and area growth rate of head of gravity currents will increase.
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Ju, Jinn-Keh, and 朱晉克. "The Characteristics of Nonpoint Sources Loading in Developed Sloping Watersheds." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/27741186684886013007.
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Chang, Ching-Min, and 張慶民. "Experiments on the evolution of submerged berms on sloping bottoms." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/84453006455216218490.
Full textAbstract:
碩士國立成功大學
水利及海洋工程學系碩博士班
93
The present study depicts the evolution process of submerged berms on sloping bottoms. To protect beaches against erosion has been an important issue of coastal engineering design. Traditional coastal protection measures have been almost hard structures. However, they often cause other problems, such as corrosion on the toe of the sea-dike or unsightly scenery and so on. Standing on the point of view in harmonic with the natural, the construction method of coast protection has been led into soft-works gradually. The experiments were conducted in a glass-side walled wave flume. The wave flume was 25m long, 0.3m wide and 0.7m deep. Grains of density, 2.45, and median grain diameter, 0.32mm, were used as the testing sediment. Two bottom slopes, 1:10 and 1:40 were simulated and they represented a steep and a gentle slope respectively. To compare with those completed under a constant water depth by Hwang et al. (2003), similar input conditions were used. Two initial submerged berm shapes with different berm heights were used under the same volume. The Shields parameter was between 0.038 and 0.095. The development of bottom geometry was measured by image processing method in every 15 minutes. The result showed that when berm was placed on a sloping bottom, sediments would move offshore and onshore. As the berm was placed on the steeper slope, the influence of gravity became stronger and this caused more volume move offshore. It thus indicated that the berm was not suitable placing on a steeper slope. In order to quantify the amounts of sediment transport from the berm, the percentage of disappearing, R, was defined. The percentage of disappearing increases with the Shields parameter. Since the berm is suggested to be applied on a gentle slope, an dimensionless averaged transport rate was formulated in terms of the Shields parameter. The critical Shields parameter, , was employed to distinguishing whether the berm is stable or movable. Finally, the result establishing the percentage of disappearing related to berm elevation, and percentage of disappearing related to berm width, which were applied on the engineering physically applied.
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Lee, Ching-Town, and 李景棠. "Purification of CO2 by Traveller Tree Within Sloping Land House." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/95211166856607890680.
Full textAbstract:
碩士國立中興大學
水土保持學系所
97
ABSTRACT The CO2 absorption during night hours of a Crassulacean Acid Metabolism Plant and its release internally to support the next daytime photosynthes offers a peculiar function to reduce night time CO2 concentration within house in sloping area. The further application on such a characteristics needs the followed three information: What kind plant species is available? What are the thresholds of such a function for the given species? What is the best strategy to operate the related information? This report selected traveler’s tree as the target species due to easy care, even green, and beautiful shape. In an isolated and closed room, three conclusions are reached for under the condition of no human occupation as follows: (1) CO2 concentration of this room tends to have a lower value due to low temperature at the midnight, (2) the post one hour CO2 concentration between with(case A) and without (case B) two traveler’s trees departs larger when time stepped to midnight if the initiated CO2 concentration are at background or at 2,000ppm levels, and (3) The departure of post one hour CO2 concentration between case A and case B becomes neglected, if the initiated CO2 concentration is at 4,000ppm level. However, the above findings is no longer existed under the case of one person occupation no matter what CO2 concentration level initiated, while a ceiling value of about 5,800ppm is instead found. This seems due to high CO2 concentration level, say 45,000ppm, and high moisture content of human breaths. The talent owned by the plant shows the important threshold it will act. The native species, therefore, should be paid with more attention. On the total adsorption amount of upper half night, two traveler’s tree display 20% of background concentration level. It will increase the total adsorption amount if more plants were moved in. CO2 concentration and energy reduction, is expected to make a great value in this case.
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Chen, Wei-jia, and 陳韋嘉. "Experimental studies of breaking solitary wave on impermeable sloping seawall." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/99799890297515480235.
Full textAbstract:
碩士國立成功大學
水利及海洋工程學系碩博士班
96
The main objective of this paper is to experimentally investigate the fluid-structure interaction between a plunging breaking solitary wave impinging and overtopping a smooth impermeable sloping seawall. The incident waves with different wave nonlinearity and freeboard in the present experiments can be categorized as three types: (1) a turbulent bore rushing inland and subsequently impacting and overtopping on the seawall, (2) a plunging breaking wave directly impinging and then overturning on the seawall and (3) a wave straightforwardly overturning over the seawall. Detailed measurements on free surface evolution, dynamic impact pressure, total overtopping discharge and subsequent run-up behaviors in the vicinity of seawall are systematically reported. Qualitative laboratory information by using the high-speed camera photography are also undertaken to observe detailed wave evolution courses. The maximum impact pressure distribution with regard to all cases on the seawall are examined and discussed. The kinematic properties of run-up and total overtopping discharge are also discussed by comparing against the available empirical formulae. Based on our analyses, it is found that the time history of dynamic pressure has an inclination to that of local free surface elevation except the instant of wave impingement. In addition, we also found that the presence of seawall can approximately reduce 20 % the maximum run-up height compared to the case where the seawall is absence. Eventually the total overtopping discharge is summarized and is compared with the available model. Fairly good agreements are achieved.
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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 textAbstract:
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.
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Hu, Chia-Sheng, and 胡嘉昇. "A Laboratory Study of the Sedimentation on a Sloping Beach." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/46445796285755330856.
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碩士淡江大學
水資源及環境工程所
82
The study is done with a rectangular section of water tank with the sizes of length、width and height is 30 m、0.8 m and 0.8 m, respectively.We make waves with a piston-type wave maker.Then we use different kinds of slopes、wave heights and wave periods pass through the channel with a sandy bed. During the waves pass by,it will change the bed of the channel.We consider situations among the different wave conditions and slopes to investigate the sedimentation on this sloping sandy beach. Finally,we also discuss the effects of smooth fixed-shape bed and rough fixed-shape bed on the wave run-up.We also compared and discussed the equations,which were taken by some researcher with the results of this study.
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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.
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Chen, Da-Wei, and 陳大煒. "Overtopping Waves-Induced Coastal Flooding over Typhoon-Failed Sloping Seawall." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/71622435109778346201.
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碩士國立臺灣海洋大學
河海工程學系
95
This study combines SWAN model and Yang’s (2000) Physiographic Inundation model to simulate time series of typhoon-induced coastal flooding in Taiwan. For land boundary conditions, the SCS Curve Number method was adopted to calculate the flow of effective rain-intensity. For sea boundary conditions, real-time sea water levels including tides and typhoon surges, and calculated wave conditions by SWAN, are input for deriving overtopping rates. The studied flooding areas include Miaoli coast during Typhoon Herb in 1996 and Hualien coast during Typhoon Longwang in 2005. Effects of sloping seawalls and typhoon-induced partial wall failures on overtopping due to are taken into account. Several existing overtopping formulae are first collected and evaluated for application in present study. The results in different areas during the same typhoon show that Owen’s(1980) calculations are slightly smaller than Schüttrumpf’s (2001) in Hualien coast but slightly larger in Miaoli coast. On the other hand, in Hualien coast during attack of Typhoon Herb (1996) and Typhoon Longwang (2005), mean overtopping rate by Schüttrumpf’s is larger than Owen’s by 4.8% and 18.7%. But during the same two typhoons, Owen’s is larger than Schüttrumpf’s by 31.0% and 5.8% in Miaoli coast. By accounting the effects of wall failures with Schüttrumpf’s formulae, the calculated overtopping rates in Miaoli coast with reduced crest height from +4.6m to +4.0m and +3.0m become larger by 21.2% and 42.1% during Typhoon Herb. Meanwhile, calculated overtopping flows in Hualien coast with reduced crest height from +10.0m to +9.0 and +8.0m become larger by 27.7% and 41.4% during Typhoon Longwang. The simulated coastal flooding has been further evaluated on three effects of rainfall, overtopping and wall failure. The results illustrate that the deficiency in height of seawall crest allows greater overtopping flows to flood in Miaoli coast. The flooding events in Hualien coast are mainly due to wall failures. Based on physiographic features with neglection of river flows, it is found that the flood recession system in Miaoli coastal area consists of Xi-hu river in the north, Nei-hu river in the east and Tong-siao river in the south. In Hualien coastal area, the flood recession system consists of Ji-an River in the north and Hualien river in the south. Keywords: overtopping, sloping seawall, wall failure, coastal flood, typhoon
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Wu, Yi-Xuan, and 吳怡萱. "The Evolution of Non-linear Wave Components on Sloping Bottom." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/10918915804013531670.
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碩士國立成功大學
水利及海洋工程學系碩博士班
93
The characteristics of wave trains in shallow water are quite different from which in deep water. Therefore, further investigations on the characteristics of wave propagation in shallow water are necessary to design suitable coastal structures. For this purpose, a series of experiments were conducted in a super tank (300m*5m*5.2m) on slopes of 1/10 and 1/20 at Tainan Hydraulics Laboratory (THL). Three kinds of wave trains (regular wave, three wave, and bichromatic wave) with a large range of initial nonlinear parameters (k0a0) were conducted in the constant deep water depth and then progressing on slopes of 1/10 and 1/20. The wave surface elevations were recorded by 93 wave gauges and analyzed by using the Fast Fourier transform (FFT) to investigate the evolution of corresponding spectrum on slopes. In order to describe the evolvement of the wave trains, nine testing runs were examined in the thesis. The results show that the evolutional characteristics of nonlinear waves depend on the initial wave types, wave steepness, bottom slopes and time and space distributions. There is no non-linear development in deep water under conditions of smaller wave steepness parameters (k0a0~0.1) for regular waves and three waves. However, as the wave trains progress on the slope, the energy of second and third harmonics grows obviously. Additionally, under conditions of larger wave steepness, regular wave trains in deep water will be unstable due to side-band instability and lead to frequency-downshift accompanying wave breaking. The energy of fundamental frequency will be transferred to lower frequency band of the spectrum. When wave trains progress on slope, the second or third harmonics derived from the shoaling effect will be at the double or triple of downshifted frequency, not the initial fundamental frequency. During three wave testing runs, the larger wave steepness parameters, the more obvious extent of wave modulated; the energy of the broken wave in deep water will shift toward the lower side-band frequency. When waves proceed on slopes, the double fundamental frequency derived from shoaling effect will also derive its two side-bands. For bichromatic waves, the evolution of specific Fourier components were examined, including two carriers(fl、fu), higher imposed side-band(2fu-fl), bounded long wave(fu-fl), double frequency of two carriers(2fl、2fu), compound of two carriers(fu+fl) and component of fu+2fl. When waves propagate in deep water, the energy of bounded long wave and higher imposed side-band will increase obviously. Additionally, the energy will grow obviously at the double Fourier component of two carriers and compound of two carriers as wave progresses on the slopes.
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HU, QIONG-WEN, and 胡瓊文. "A study of the sedimentation along the sloping sandy beach." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/28589188774430597590.
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zeng, wei-ming, and 曾偉銘. "The Assessment of Critical Hydraulic Gradient for Sloping Fields Piping." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/87883632252261962369.
Full textAbstract:
碩士中原大學
土木工程研究所
96
The piping phenomenon means that soil particles move along the pathway among particles of the soil-body framework or when soil particles are taken out from the soil-body. The position of piping phenomenon occurs seepage outlet or inside of siol-body.In general, We come to obtain the hydraulic gradient by way of whole, but the data we got that is the average hydraulic gradient; On the other hand the sandy soil when includes the moisture content has the cohesive force, but in the tradition actually neglects this value, it causes the hydraulic gradient not to be certainly precise when piping phenomenon occurrence. The research uses critical hydraulic gradient equation and GMS to observe the hydraulic gradient of soil particle in the piping phenomenon. Firstly, this research involves the model experiment on lab piping phenomenon. Selects the material first group for pass 50 sieve and stops 60 sieve of standard sand, the second group for mixes sand.Secondly, we build critical Hydraulic Gradient equation that is derived from movement equations. Thirdly, according to parameter condition and boundary condition which were got from the experimental result, that bring into GMS and get the velocity of fluid and the hydraulic gradient by GMS. Finally, the research analyzes the different result under different conditions between three methods, and revises its cohesive strength and effective friction angle.The research uses piping phenomenon experiment, the theory formula and GMS to analyze the hydraulic gradient, and compares each other, three quite approaches in the critical hydraulic gradient aspect; obtains the cohesive strength scope between 0.0660and 0.0891(N/cm2),as for the effective friction angle, dank sand is slightly bigger than dry sand for 0.8°~2.0°, may supply in the project to refer.
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Shiau, Yeong-Ming, and 蕭永明. "Analytical solutions for groundwater flow on sloping bed with uniform recharge." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/70955332091775908449.
Full textAbstract:
碩士國立中央大學
土木工程研究所
90
Abstract The major purpose of this study is to obtain a new approximation for seepage flow over a sloping bed. This study is based on Childs’ theory. The streamlines are assumed to be nearly pararell to the sloping bed, and coordinate s pararell to the bed is used to calculate the hydraulic gradient. In the process, variables translation and the Newton-Raphson interation method are applied to obtain the solution of phreatic surface, which is in form of the function of the derivative of free surface, P. The maximum water table height hmax and its location smax could be easily obtained, and are well coincident with previous published studies. The solution developed here could not only deal with problems with various upstream and downstream depths, but also could be used to explore mixed boundary value problems. The analytical results can be used to evaluate the effects of slope, replenishment, and hydraulic conductivity on the preatic surface. The solution is applied to a case study of a debris flow event.
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Hsiang, Chou Tze, and 周子祥. "The Flow Structrues and Formation of Sand Ripples on Sloping Bottom." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/22217702766598965548.
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