Дисертації з теми "Kinematic waves"
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1
Ni, Daiheng. "Extension and generalization of Newell's simplified theory of kinematic waves." Diss., Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-11112004-112805/unrestricted/ni%5Fdaiheng%5F200412%5Fphd.pdf.
Анотація:
Thesis (Ph. D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2005.Leonard, John D., Committee Chair ; Goldsman, Dave, Committee Member ; Amekudzi, Adjo, Committee Member ; Hunter, Michael, Committee Member ; Dixon, Karen, Committee Member. Vita. Includes bibliographical references.
2
Vieth, Kai-Uwe. "Kinematic wavefield attributes in seismic imaging /." [Karlsruhe] : Die Universität, 2001. http://www.ubka.uni-karlsruhe.de/vvv/2001/physik/2/2.pdf.
3
Mukhamediyarova, Akerke. "Microbiological Enhanced Oil Recovery : Model of Kinematic Waves and Asymptotic Analysis." Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0301.
Анотація:
L’un des objectifs stratégiques de l’industrie pétrolière moderne est le développement réserve effective de pétrole à haute viscosité, caractérisées par une faible mobilité entraînant une forte baisse du facteur de récupération du pétrole. Le développement de tels réservoirs par des méthodes traditionnelles (déplétion naturelle, injection d’eau, etc.) n’est souvent pas efficace. L’alternative est une application de méthodes de récupération actives, en d’autres termes, des méthodes de récupération assistée du pétrole. Dans cette thèse, nous analysons les problèmes de modélisation du déplacement du pétrole par l’eau en présence de bactéries produisant des agents chimiques actifs qui changent favorablement les propriétés du pétrole et de l’eau. Plus strictement, nous analysons les bactéries produisant un biosurfactant qui réduit les effets négatifs du piégeage d’huile capillaire en milieux poreux. Un tel problème fait partie de la théorie générale de l’écoulement multiphase multicomposant partiellement miscible avec des réactions chimiques, couplé à la dynamique de la population. Le modèle mathématique général du processus est présenté, qui a été réduit au modèle des ondes cinématiques, grâce à plusieurs simplifications admissibles. Plus exactement, nous avons obtenu le système de cinq équations différentielles en dérivées partielles non linéaires du premier ordre, qui peuvent avoir des solutions discontinues. Un tel système ne peut être étudié que numériquement dans le cas général. Cependant, nous avons montré que pour un cas particulier, ce modèle peut être complètement analysé qualitativement. Pour une telle analyse, nous avons introduit le concept de faible bioréactivité. Elle correspond au comportement asymptotique du modèle général lorsque le taux de cinétique bactérienne tend vers zéro. En appliquant la technique de développement asymptotique, nous avons obtenu la solution semi-analytique du problème de déplacement. En particulier, cela nous a offert la possibilité de détecter les discontinuités (les chocs) de différents types et d’analyser exactement leur structure. Le cas général du taux cinétique arbitraire a été étudié numériquement, en utilisant le code COMSOL MULTIPHYSICS. Nous avons analysé l’impact du taux de croissance microbien, des concentrations microbiennes et nutritives, de la forme des fonctions cinétiques et du rapport de viscosité sur la récupération de l’huile. Dans le dernier chapitre, nous avons simulé un cas réel d’un champ pétrolier kazakh. Le principal et unique outil d’étude de la récupération microbiologique assistée du pétrole (RAMP) était l’analyse numérique, alors qu’il manquait des solutions analytiques. Les solutions semi-analytiques que nous avons obtenues comblent cette lacune. Ils représentent des résultats exacts qui pourraient être utilisés pour vérifier la validité de divers schémas et codes numériquesOne of the strategic objectives of the modern oil industry is the efficient development of high-viscosity oil reserves, which are characterized by low mobility leading to a sharp decline in the oil recovery factor. The development of such reservoirs by traditional methods (natural drives, waterflooding etc.) is frequently not efficient. The alternative is an application of active recovery methods, in other words, enhanced oil recovery methods. In this thesis we analyze the problems of modelling the displacement of oil by water in presence of bacteria producing some active chemicals that change favorably the properties of oil and water. More strictly, we analyze the bacteria producing biosurfactant that reduces the negative effects of capillary oil trapping in porous media. Such a problem makes part of the general theory of multiphase multicomponent partially miscible flow with chemical reactions, coupled with the dynamics of population. The general mathematical model of the process is presented, which is reduced next to the model of kinematic waves, due to several admissible simplifications. More exactly, we have obtained the system of five nonlinear partial differential equations of the first order, which can have discontinuous solutions. Such a system can be studied only numerically in the general case. However, we have shown that for a particular case this model can be completely analyzed qualitatively. For such an analysis, we have introduced the concept of weak bioreactivity. It corresponds to the asymptotic behavior of the general model as the rate of bacterial kinetics tends to zero. Applying the technique of asymptotic expansions, we have obtained the semi-analytical solution to the displacement problem. In particular, this offered us the possibility to detect the discontinuities (chocks) of various types and to analyze exactly their structure. The general case of arbitrary kinetic rate was studied numerically, by using the code COMSOL MULTIPHYSICS. We analyzed the impact of the microbial growth rate, microbial and nutrient concentrations, the form of kinetic functions and the viscosity ratio on the oil recovery. In the last chapter, we simulated a field case for a Kazakhstani oil field. The main and unique tool of studying MEOR was the numerical analysis, whilst analytical solutions were missing. The semi-analytical solutions we have obtained fill this gap. They represent exact results that could be used to check the validity of various numerical schemes and codes
4
Gomes, Vanessa Ueta. "Comparative studies between the kinematic and diffusive waves on the flood routing analisys, in function of hydraulics parameters of the watershed." Universidade Federal do CearÃ, 2006. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=242.
Анотація:
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoOs Modelos da Onda CinemÃtica e da Onda Difusiva foram aplicados em um rio natural, para estudar a propagaÃÃo de uma onda de cheia neste corpo hÃdrico. Esses modelos sÃo derivaÃÃes do Modelo da Onda DinÃmica, a partir de simplificaÃÃes nas EquaÃÃes de Saint Venant, onde alguns termos sÃo desprezados. No processo de soluÃÃo das equaÃÃes diferenciais, pertinentes aos modelos, foi usado o MÃtodo das DiferenÃas Finitas, sendo que o esquema de aproximaÃÃo explicita foi aplicado para a onda cinemÃtica, enquanto que o esquema de aproximaÃÃo implÃcita foi aplicado para a onda difusiva. Para esta pesquisa, um programa computacional, em linguagem FORTRAN, foi desenvolvido e permitiu que viÃrias simulaÃÃes fossem realizadas, para diferentes cenÃrios encontrados nos rios naturais. Estudos para verificar a sensibilidade dos modelos, com respeito aos parÃmetros hidrÃulicos da bacia, foram realizados. TambÃm foi verificada a influÃncia da linearizaÃÃo das equaÃÃes diferenciais, que compÃem os modelos, nÃs cÃlculos das variÃveis de controle. Os resultados mostraram que o modelo da onda cinemÃtica à mais sensÃvel ao coeficiente de rugosidade das paredes do canal, enquanto que o modelo da onda difusiva à mais sensÃvel para parÃmetros da declividade de fundo do canal, onde este parÃmetro atua diretamente no processo de amortecimento da onda em propagaÃÃo. Os resultados mostraram ainda que, para os cenÃrios usados nas simulaÃÃes, o processo de linearizaÃÃo das equaÃÃes diferenciais nÃo afeta, consideravelmente, a soluÃÃo dos modelos.
5
Athanasiou, Evangelia. "Response on reinforced concrete structural elements to ballistic impact and contact detonations." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31287.
Анотація:
Concrete is a widely studied material with a composite nature. It is used both in civil and military buildings and infrastructures. An issue of great importance is the protection of people from terrorist attacks that target critical infrastructure. Explosions, detonations and/or projectile impacts are some of the most severe actions a concrete structure can face. Experimental analysis is necessary in order to understand and predict the response of a structure to such dynamic and strain rate sensitive conditions. However, as the cost of performing experiments is significant and numerical simulations offer improved blast and impact analysis capabilities, there is an effort to limit experiments to validation purposes. In recent years, many researchers have studied the impact loads transferred to reinforced concrete (RC) structures both through direct projectile impacts or blast waves at both near and far field. The aim of the current study is twofold. First, to investigate contact detonations on this type of material (RC), since literature can provide us with limited information. Secondly, to assess the behaviour of the RC structure under combined ballistic impact and contact detonation of a very specific geometry of projectile (HESH) that exists currently on the market and behaves differently from the normal projectiles that consist of one single material. The author analysed and discussed in depth the response of RC members exposed to contact detonations. More precisely, the effect of the mass of explosive (C4) on pressures, impulses and energy balances. Also, she investigated the kinematic response of RC slabs and the structural role of the reinforcing bars. The driving force of this RC structures. Currently, the majority of studies regarding contact blast are focusing either on innovative types of concrete or normal concrete. However, normal concrete is investigated as a control parameter (to prove the effective resistance of the innovative material) rather than a detailed study on the behaviour of the material. Thereafter, the author analysed the response of a RC wall under the combined effect of kinetic energy (terminal ballistics) and contact detonation caused by the impact of a 90 mm HESH (High Explosive Squash Head) projectile fired from a distance of 70 m. The aim was to investigate the response of the structural member under the superposition of those two actions and analyse the combined effects of the impact velocity and detonation on the response of the structure. The numerical modelling is based on a Multi-Material-Arbitrary-Lagrangian-Eulerian approach (MMALE, using LS-DYNA) using the Winfrith concrete constitutive material model to investigate the dynamic response of the RC members under high strain rate conditions. The efficiency of the proposed numerical modelling is validated with experimental results - based on open-arena testing - and provided by the Royal Military Academy of Belgium. Some of the key findings of this research are that the increase of the amount of the explosive affects the damage failure of the RC members from flexural failure to shear failure. In addition, fitting curves that could be used in design, were proposed, that show the relation between the mass of explosive and the resulting pressures and impulses, within the tested range. In the case of the combined blast and impact scenario, the detonation was found to dominate the structural response of the RC slab.
6
Abreu, Manuel P. "Kinematics under wind waves." Thesis, Monterey, California. Naval Postgraduate School, 1989. http://hdl.handle.net/10945/27115.
7
Lader, Pål Furset. "Geometry and Kinematics of Breaking Waves." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Engineering Science and Technology, 2002. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-69.
Анотація:
The objective of this thesis is to experimentally study different breaking waves cases. This is done by measuring in detail the free surface geometry and the internal kinematics of the waves as they approach breaking. Three principal wave cases were chosen for the study: A plunging breaker, a spilling breaker, and an intermediate breaker.
A major part of this work is the design, construction and building of a wave laboratory. The laboratory contains a glass wall waveflume which is 13.5m long, 1m deep and 0.6m wide, as well as equipment for measuring both the wave kinematics and geometry optically. The wave kinematics is measured using the Particle Image Velocimetry (PIV) method, while the wave profile geometry is measured using image analysis (space domain geometry), as well as standard wave gauges (time domain geometry).
The analysis of both the wave kinematics and geometry is done using parameters describing quantitatively important features in the wave evolution. The surface geometry is described using the commonly known zero-downcross parameters, and in addition, new parameters are suggested and used in the study, The kinematics are described by a set of four parameters suggested for the first time in this work. These parameters are: Velocity at the surface, velocity at the still water line (z = 0), mean velocity direction, and local wave number. The purpose of these parameters is to give a better understanding of the space and time domain development of the kinematics, and they appear to be a reasonable compromise between simplicity and accuracy.
The results presented here represents a thorough and detailed mapping of the breaking process. Much data is gathered and analysed, and throughout this thesis it is sought to present the data in the most intuitive way, so that other investigations may benefit from it.
8
Constantian, Richard K. "Observed kinematics of waves in the surf zone." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1999. http://handle.dtic.mil/100.2/ADA361813.
Анотація:
Thesis (M.S. in Physical Oceanography) Naval Postgraduate School, March 1999."March 1999". Thesis advisor(s): T.H.C. Herbers. Includes bibliographical references (p. 41-42). Also available online.
9
Jin, Wenlong. "Kinematic wave models of network vehicular traffic /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.
10
Kleiss, Jessica M. "Airborne observations of the kinematics and statistics of breaking waves." Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3359574.
Анотація:
Thesis (Ph. D.)--University of California, San Diego, 2009.Title from first page of PDF file (viewed July 22, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 181-190).
11
Choi, Hae-Jin. "Kinematics measurements of regular, irregular, and rogue waves by PIV/LDV." Texas A&M University, 2005. http://hdl.handle.net/1969.1/4797.
Анотація:
A comprehensive experimental study was conducted to produce benchmark wave
kinematics data for five different regular waves and the maxima of four different irregular
wave trains. Two of the irregular waves generated are in the category of rogue waves. A
series of experiments were conducted in a 2-D wave tank at Texas A&M University to
measure wave velocities and accelerations using LDV and PIV systems. The wave crests
of regular and rogue waves are the focus of this study. With the measured wave velocity
field, the wave accelerations were computed using a centered finite difference scheme.
Both local and convective components of the total accelerations are obtained from
experimental data. Also, the nonlinear wave forces on a truncated slender cylinder are
computed by applying the obtained wave kinematics to the Morison equation. The force
results based on measured wave kinematics are compared with those based on the
kinematics of linear extrapolation, Wheeler stretching, and modified stretching. The
Wheeler stretching method generally underestimates the actual wave kinematics. The
linear extrapolation method is very sensitive to the cutoff frequency of the wave spectrum.
The modified stretching method tends to predict the maximum value of wave kinematics
above the still water level (SWL) well except for the convective acceleration. The magnitude of convective acceleration in the regular waves was negligibly small, whereas
the magnitudes of horizontal and vertical convective accelerations in the rogue wave were
increased rapidly above the SWL.
12
Ojieh, Nwaka Chuks. "On the kinematics of an alternative extreme wave." Thesis, University of Strathclyde, 2009. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=11538.
13
Martin, Alastair John. "Laboratory simulation and numerical modelling of the kinematics of oceanic internal waves." Thesis, University of Edinburgh, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.521532.
14
Chau, Fun Pang. "The second order velocity potential for diffraction of waves by fixed offshore structures." Thesis, University College London (University of London), 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296841.
Анотація:
It is well known that second order effects may in many cases be important for the nonlinear hydrodynamic problems arising in ocean engineering. Despite considerable efforts having been made in the past in calculating second order unsteady forces, similar studies are rare for the actual second order velocity potential itself, which is important for the understanding of wave kinematics. A mathematical model has been developed for the calculation of the second order sum frequency diffraction potential for fixed bodies in waves. It is believed that a first step towards the solution of the second order problem is the accurate evaluation of the first order quantities. By the use of Green's second identity, the first order problem can be cast into the form of a Fredholm integral equation and then solved by the Boundary Element Method. Some new developments based on this technique have been undertaken in this work, and as a result, there is a major improvement in the accuracy of the first order analysis. For the second order problem, the solution procedures are similar to those used for the first order problem except that special techniques have been developed to calculate efficiently the additional free surface integral which decays slowly to infinity in a highly oscillatory manner. In addition, an effective method has also been implemented to calculate the second derivative term in the free surface integral. From the numerical results presented, a number of interesting findings are illustrated. A closed form expression for a vertical circular cylinder has also been developed which not only furnishes a valuable check on the general numerical model but also provides some physical explanation for the second order phenomena. Moreover, it has been used to investigate some theoretical problems which (in the past) have caused confusion and error in the second order analysis. They are mainly associated with the troublesome nonhomogeneity presented in the free surface boundary condition.
15
Emmons, Megan R. "Effects of Communication Delay and Kinematic Variation in Vehicle Platooning." DigitalCommons@USU, 2013. https://digitalcommons.usu.edu/etd/1752.
Анотація:
Vehicle platoons are efficient, closely-spaced groups of robotically controlled vehicles which travel at high speeds down the road, similar to carts in a train. Within this thesis, a promising control algorithm for vehicle platooning is explored. The control algorithm was previously demonstrated in a sterile setting which significantly reduced the challenges facing full-scale implementation of platoons, most notably loss of shared data and imprecision within the data. As found within this work, transmission loss and imprecise position, velocity, and acceleration data significantly degraded the control algorithm's performance. Vehicles in the platoon became more closely spaced, changed speeds more frequently, and expended far more energy than necessary. Introducing a measure of each following vehicle's position with respect to the lead vehicle into the control algorithm noticeably reduced platoon contraction. Adjusting the control algorithm's responsiveness based on what data was successfully received reduced the speed-variations by vehicles. Finally, using past behavior to predict the next acceleration reduced the energy used by each vehicle. Combining these modifications with a model of the proposed communication scheme shows platoons of up to 25 vehicles are feasible.
16
Seaman, Roy C. "Beach response in front of wave-reflecting structures." Thesis, University of Aberdeen, 1998. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU105978.
Анотація:
Several studies have previously demonstrated that sediment transported as bed load under a standing wave will be moved from between node and antinode towards the node where it accumulates. The end result is the generation of areas of scour in the bed between node and antinode and areas of sediment accretion around the node. However, these studies have failed to provide an adequate description of the mechanisms which led to this so-called "N-type" response. Consequently it has been the purpose of this study to examine the phenomenon of N-type beach response in some detail. As a first step an experimental programme was conducted in a random wave flume using a model beach and vertical, impermeable wall N-type conditions were produced, observations are made on the mechanisms of sediment transport and flow-field measurements are also reported. The experimental results demonstrate that N-type beach response is the direct result of an asymmetry in the main flow-field caused by the superposition of incident and reflected non-linear waves. A second experimental programme examines the N-type equilibrium profile shape using measurements of profiles generated under a range of wave conditions. An equation defined for a given profile amplitude and profile limits is found to predict the underlying characteristic N-type profile shape very well. Finally, a model of N-type beach response is developed. This model follows a relatively simple "grab-and-dump" concept with coefficients based on the understanding gained of the N-type response processes. It is shown that N-type profiles can be predicted reasonably well for the range of wave conditions used in the experiments here. Outside of this range predictions are less good, suggesting a re-examination of the model coefficients is required.
17
Jones, Samuel Edward. "Symmetries in the kinematic dynamos and hydrodynamic instabilities of the ABC flows." Thesis, University of Exeter, 2013. http://hdl.handle.net/10871/14689.
Анотація:
This thesis primarily concerns kinematic dynamo action by the 1:1:1 ABC flow, in the highly conducting limit of large magnetic Reynolds number Rm. The flow possesses 24 symmetries, with a symmetry group isomorphic to the group O24 of orientation-preserving transformations of a cube. These symmetries are exploited to break up the linear eigenvalue problem into five distinct symmetry classes, which we label I-V. The thesis discusses how to reduce the scale of the numerical problem to a subset of Fourier modes for a magnetic field in each class, which then may be solved independently to obtain distinct branches of eigenvalues and magnetic field eigenfunctions. Two numerical methods are employed: the first is to time step a magnetic field in a given symmetry class and obtain the growth rate and frequency by measuring the magnetic energy as a function of time. The second method involves a more direct determination of the eigenvalue using the eigenvalue solver ARPACK for sparse matrix systems, which employs an implicitly restarted Arnoldi method. The two methods are checked against each other, and compared for efficiency and reliability. Eigenvalue branches for each symmetry class are obtained for magnetic Reynolds numbers Rm up to 10^4 together with spectra and magnetic field visualisations. A sequence of branches emerges as Rm increases and the magnetic field structures in the different branches are discussed and compared. All symmetry classes are found to contain a dynamo, though dynamo effectiveness varies greatly between classes, suggesting that the symmetries play an important role in the field amplification mechanisms. A closely related problem, that of linear hydrodynamic stability, is also explored in the limit of large Reynolds number Re. As the same symmetry considerations apply, the five symmetry classes of the linear instability can be resolved independently, reducing the size of the problem and allowing exploration of the effects of the symmetries on instability growth rate. Results and visualisations are obtained for all five classes for Re up to 10^3, with comparisons drawn between the structures seen in each class and with those found in the analogous magnetic problem. For increasing Re, multiple mode crossings are observed within each class, with remarkably similar growth rates seen in all classes at Re=10^3, highlighting a lack of dependence on the symmetries of the instability, in contrast with the magnetic problem. This thesis also investigates the problem of large-scale magnetic fields in the 1:1:1 ABC flow through the introduction of Bloch waves that modify the periodicity of the magnetic field relative to the flow. Results are found for a field with increased periodicity in a single direction for Rm up to 10^3; it is established that the optimal scale for dynamo action varies as Rm increases, settling on a consistent scale for large Rm. The emerging field structures are studied and linked with those of the original dynamo problem. On contrasting this method with a previous study in which the flow is instead rescaled, it is shown that the use of Bloch waves drastically increases the range of possible scales, whilst cutting required computing time. Through a multiple-scale analysis, the contribution from the alpha-effect is calculated for the 1:1:1 ABC flow and is seen in growth rates for Rm << 1.
18
Cheah, Chin Hong Civil & Environmental Engineering Faculty of Engineering UNSW. "Kinematic wave modelling of surface runoff quantity and quality for small urban catchments in Sydney." Awarded By:University of New South Wales. Civil & Environmental Engineering, 2009. http://handle.unsw.edu.au/1959.4/44618.
Анотація:
Extensive research has been undertaken to improve the robustness of runoff quantity predictions for urban catchments. However, equally robust predictions for runoff quality have yet to be attained. Past studies addressing this issue have typically been confined to the use of simple conceptual or empirical models which forgo the tedious steps of providing a physical representation of the actual system to be modelled. Consequently, even if the modelling results for the test catchments are satisfactory, the reliability and applicability of these models for other catchments remain uncertain. It is deemed that by employing process-based, deterministic models, many of these uncertainties can be eliminated. A lack of understanding of the hydrological processes occurring during storm events and the absence of good calibration data, however, hamper the advancement of such models and limit their use in the field. This research proposes that the development of a hydrologic model based on the kinematic wave equations linked to an advection-dispersion model that simulates pollutant detachment and transport will improve both runoff quantity and quality simulations and enhance the robustness of the predictions. At the very worst, a model of this type could still highlight the underlying issues that inhibit models from reproducing the recorded historical hydrographs and pollutographs. In actual fact, this approach has already been applied by various modellers to simulate the entrainment of pollutants from urban catchments. Also, the paradigm shift to using the Water Sensitive Urban Design (WSUD) approach in designing urban stormwater systems has prompted the need to differentiate the various sources of pollutants in urban catchments such as roads, roofs and other impervious surfaces. The primary objective of the study reported herein is to model runoff quantity and quality from small urban catchments, facilitated by the procurement of the necessary field data to calibrate and validate the model via implementation of a comprehensive field exercise based in Sydney. From a water quality perspective, trace metals were selected as the foci. The study outcomes include the formulation of a linkage of models capable of providing accurate and reliable runoff quantity and quality predictions for the study catchments by taking into consideration: - The different availability of pollutants from urban catchments, i.e. roads vs. roofs; - The build-up characteristics of pollutants on the distinct urban surfaces and their spatial distribution; - The contribution of rainwater to urban runoff pollution; - The partitioning of pollutants according to particulate bound and dissolved phases; - The respective role of rainfall and runoff in the detachment and entrainment of pollutants; - The influence of particle properties such as particle size distribution and density on pollutant transport; and - The relationship associating particulate bound metals to suspended solids. The simulation results obtained using the proposed model were found to be suitable for modelling the detachment and transport of pollutants for small urban catchments. Interpretation of these results reveals several key findings which could help to rectify shortcomings of existing modelling approaches. Even though the robustness of the model presented here may not translate into a significant improvement in the overall robustness of model predictions, the physical basis on which this process-based model was developed nevertheless provides the flexibility necessary for implementation at alternative sites. It is also shown that the availability of reliable runoff data is essential for implementation of the model for other similar urban catchments. In conclusion, the proposed model in this study will serve as a worthy tool in future urban catchment management studies.
19
Leung, Ka-Ho Derek. "Shock Tube Design and the Kinematics of the Hybrid III Dummy Head under Shock Waves of Blast." Thesis, North Dakota State University, 2012. https://hdl.handle.net/10365/26832.
Анотація:
Traumatic brain injury (TBI) is one of the most common injuries to soldiers in warfare today. A TBI occurs when the human brain is damaged by a sudden force coming from the environment. In the combat field of combat, high pressure blasts generated by improvised explosive devices (IEDs) are a constant threat and because of the sudden force of the blast wave are a major cause of the TBIs. Blasts created by IEDs can also cause damage to other human body parts including lungs, bowels, and any other air-containing organs. In this study, a blast shock tube was constructed for use with a Hybrid III dummy head model along with pressure sensors and accelerometers to obtain mechanical behavior data from when the generated compressed air is released from the driver section of the blast shock tube. As linear acceleration is one of the major factors in TBIs occurring, the main objective of this study was to determine the linear acceleration of the Hybrid III dummy head when hit by the pressure pulse generated by the blast shock tube. To generate the pressure pulse for mimicking the blasting scenario, a blast shock tube was constructed, with which the linear acceleration of the Hybrid III head could be found. The relationships between the pressure pulse. The acceleration and the standoff distance could then be determined. The velocity of the dummy head was identified using a high-speed camera and a simple model was established for finite element (FE) analysis. The computational results showed that the closer the dummy head was to the shock tube opening, and the higher the pressure pulse being used, the higher the maximum velocity and acceleration of the dummy head and the higher pressure experienced on the dummy head.United States Army
NDSU Mechanical Engineering Department
20
Kumar, Nishant. "Towards practical implementation of computational solution of the Kinematic -wave Model for simulating traffic-flow scenarios." Thesis, Texas A&M University, 2004. http://hdl.handle.net/1969.1/1037.
Анотація:
The Kinematic-wave model is one of the models proposed to simulate vehicular traffic. It has not received widespread use because of poor understanding of associated interface conditions and early use of incorrect numerical schemes used. This thesis analyzes mathematically correct boundary and interface conditions in the context of the Godunov method as the numerical scheme for the simulation software created. This thesis simulates a set of scenarios originally proposed by Ross, to verify the validity of simulation. The results of the simulation are compared against the corresponding results of Ross, and against intuitive expectation of the behavior of actual traffic under the scenarios. Our results tend either to agree with or improve upon those reported by Ross, who used alternate models.
21
Raby, Alison Caroline. "Extreme waves, overtopping and flooding at sea defences." Thesis, University of Oxford, 2003. http://ora.ox.ac.uk/objects/uuid:82fcc770-8838-4f9b-9abe-32eecdd05f9a.
Анотація:
This thesis describes experiments that were carried out using focused wave groups in the UK Coastal Research Facility (UKCRF). Considerable effort was put into calibrating the UKCRF to determine the relationship between the input signals sent to the paddles and the waves generated in the facility. Focused wave groups of various sizes and phases, based on NewWave theory were generated, and measurements were made of the resulting surface elevation data, water particle kinematics, wave runup and overtopping volumes. NewWave theory models the profile of extreme waves in a Gaussian (random) sea. The thesis describes the first time this model has been applied in the context of coastal wave transformation. A method for the separation of the underlying harmonic structure of a focused wave group is described and results presented. This technique has been used in relatively deep water but is shown to work successfully in the coastal zone until wave overturning. A method has been devised to provide a theoretical Stokes-like expansion of the free and bound waves to model the surface elevation and water particle kinematics of the focused wave groups. Satisfactory agreement is achieved between the theoretical predictions of UKCRF measurements. Suggestions are made for an improved model. The underlying harmonic structure of the focused wave groups is presented as stacked time histories that give insight into the wave transformation process from deep to shallow water. Particular attention is paid to the low frequency wave generated as the wave group interacts with the beach. This is compared to the low frequency wave that is generated by a solitary wave in the UKCRF. Runup and overtopping measurements are in reasonable agreement with predictions based on certain empirical formulae, but not others. These comparisons are useful in identifying those formulae able to predict runup and overtopping of extreme waves in the coastal zone.
22
Harris, Jamie. "The kinematics, dynamics and statistics of three-wave interactions in models of geophysical flow." Thesis, University of Warwick, 2013. http://wrap.warwick.ac.uk/58419/.
Анотація:
We study the dynamics, kinematics and statistics of resonant and quasiresonant three-wave interactions appearing in models of geophysical flow. In these dispersive wave systems, the phenomenon of nonlinear resonance broadening plays a significant role across all three different branches of wave turbulence theory: from the statistical, to the discrete, and even the mesoscopic, formed as an intermediate regime between the two. The principal aim of this thesis is to understand the processes by which resonance broadening can induce a transition between each of these three different regimes. Beginning with the discrete case, we study two variants of the isolated triad: one with a constant additive forcing term; and the other in the presence of detuning. We provide a detailed analysis of both of these systems, covering their integrability and boundedness properties, showing that for almost all initial conditions the motion remains quasi-periodic and periodic respectively. Interestingly, we show that moderate amounts of detuning can actually promote energy exchange, increase the period and in rare instances cease to be periodic at all; each of these statements are contrary to what was previously thought. This motivates a more detailed study into the kinematics of resonance broadening. By analysing how the set of quasi-resonant modes develops under increased broadening, we show that a percolation-like transition exists, independent of the dispersion relationship used. At critical levels of broadening, we see the emergence of a single quasi-resonant cluster that begins to dominate the entire system. We argue that the formation of this cluster provides a way of characterising the turbulent state of the system, distinguishing between the discrete and statistical regimes. Through direct numerical simulation of the Charney-Hasegawa-Mima equation, we then assess whether this view is truly representative of the underlying dynamics. Here we find that the generation of quasi-resonantly excited modes can be detected through the statistical measures of total correlation and mutual information. We conclude by suggesting that these techniques have an incredible potential to infer the signature of both resonant and quasi-resonant clusters in fully realised turbulent systems, and yet are also subtle enough to detect qualitative changes in the underlying dynamics between different interacting modes.
23
Kyono, Hideki. "Kinematics of Conformal Field Theory and Diagrams in AdS Space." Kyoto University, 2019. http://hdl.handle.net/2433/242597.
24
Wyngaardt, Shaun Metzler. "Relativistic plane wave description of spin transfer observables for proton knockout reactions." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52429.
Анотація:
Thesis (PhD)--Stellenbosch University, 2001.ENGLISH ABSTRACT: In this dissertation we set out to develop the first relativistic model for calculating complete sets of (p, 2p) spin transfer observables. In addition to this a new technique has been developed which allows us to evaluate the transition amplitude, which is used to calculate the scattering observables for the reaction directly. The influence of various modiuin-modificd parameters ()1I the scattered wave functions anr] NN interact ion lH-IVC' })('('11 invest igatcd DlIC t,C) (I,llIlJigllitic's surrounding the nNN coupling we have included both pseudosoalar and pseudovector coupling into the nucleon-nucleon interaction model. Furthermore we have included two different kinematic prescriptions to obtain the effective NN laboratory kinetic energy and center of mass scattering angle, which are used to obtain the NN scattering amplitudes. The aim of this study is to investigate the effects of the various model parameters on complete sets of scattering observables. Our investigation has shown that although the analyzing power is not very sensitive to nuclear medium effects, and the various other spin transfer observables such as Dnn should provide valuable insight. Further refinements of the model would be to include nuclear distortions as well as the IA2 model of the NN interaction.
AFRIKAANSE OPSOMMING: In hierdie tesis ontwikkel ons die eerste relatiwistiese model vir die berekening van 'n volledige stel (p, 2p) spin waarneembares. Verder word 'n nuwe tegniek ingevoer wat ons toelaat om die oorgangsamplitude, wat gebruik word in berekening van die verstrooings waarneembares vir die reaksie, direk te evalueer. Die invloed van verskeie medium-gemodifiseerde parameters op die verstrooide golffunksies en die NN wisselwerking word bestudeer. As gevolg van onsekerhede betreffende die лNN koppeling word beide die pseudoskalaar en pseudovektor koppeling in die nukleon-nukleon interaksie model ingesluit. Ons sluit ook twee verskillende kinematiese preskripsies in om die effektiewe NN laboratorium kinetiese energie en die massa middelpunt verstrooiings hoek, wat gebruik word vir die berekening van die NN verstrooiings amplitude, te bereken. Die doel van hierdie studie is om die effek van verskeie model parameters op 'n volledige stel spin waarneembares te ondersoek. Die studie toon dat alhoewel die analiseervermoë nie baie sensitief is vir medium effekte nie, die ander spin waarneembares soos byvoorbeeld Dnn waardevolle insig lewer. Daar word voorgestel dat die model verfyn word deur kerndistorsies as ook die meer algemele IA2 model vir die NN interaksie in te sluit.
25
Crossley, George Robert Northcote. "Quantification of uncertainty in sub-sea acoustic measurement, and validation of wave-current kinematics, at a tidal energy site." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31541.
Анотація:
As developers seek to convert the energy of the tides into electricity, sub-sea turbines must be designed to perform well in increasingly harsh conditions. Such energetic seas have historically been avoided, hence measurements taken below the surface in strong tidal currents and large waves are relatively few, and the theory behind these interactions is underdeveloped. This thesis compares measurements of subsurface velocity taken in the field, at a UK site proposed for development, to the velocity outputs of a model capable of combining waves and currents in a number of ways. In particular the interaction between waves and currents is investigated. The methodology incorporates a novel virtual velocity measurement instrument to measure the model flow, replicating the physical instruments used at sea, such that direct comparisons can be made between the two data-sets. Model and field velocities show good agreement across a range of current speeds and wave heights, with a range of metrics used to demonstrate the suitability of the model, based on linear wave-current theory, for this site. The wave-current interaction module is calibrated, with linear superposition of wave and current velocities proving a suitable representation of field velocities. Calculation of a dispersion relationship affected by mean current velocity marginally improves calibration with field data. Analysis of other sites using the tools developed will further validate this type of model, which in combination with blade element momentum theory, is able to predict pre-construction site specific loads on tidal turbines. Doppler Current Profilers (DCPs) are able to measure subsurface water particle kinematics and sea surface elevation simultaneously, however assumptions made by these instruments jeopardise detail when recording in highly energetic seas, particularly where waves and turbulent tidal currents combine. Models developed to optimise the design of tidal turbines require correct site specific inputs to accurately reflect the conditions that a turbine may encounter through its lifetime, moreover, the kinematics of these models must be accurately validated. To overcome the limitations in DCP measurements a 'Virtual' Doppler Current Profiler (VDCP) is developed (Crossley et al. 2017), enabling quantification of error in site characteristics, and 'like for like' comparisons of field and model kinematics that has never previously been documented. The numerical model developed incorporates tidal currents, waves and turbulence combined linearly to output subsurface velocity based on conditions from the field which have been averaged over ten minute intervals. The inputs are simple, time averaged characteristics (current magnitude, direction, and profile; wave height, period and direction, turbulence intensity and turbulence length-scale) and the model outputs velocities over a two dimensional grid that develops with time. The VDCP samples this flow as if it were the very instrument in the field that recorded the data used for validation. Taking into account the heading, pitch and roll of the instrument a data set directly comparable to that measured in the field is generated. The VDCP is initially used in quantifying error in wave and turbulence statistics, demonstrating a phase dependency of velocity measurements averaged between beams and providing a theoretical error for wave and turbulence characteristics sampled under a range of conditions, in order to improve tidal site characterisation. Spectral moments of the subsurface longitudinal wave orbital velocities recorded by the VDCP can be between 0.1 and 9 times those measured at a point for certain turbulent current conditions, turbulence intensity measurements may vary between 0.2 and 1.5 times the input value in low wave conditions and turbulence length scale calculations can vary by over ten times the input value, dependent on both current and wave conditions. The methodology can be used to determine a theoretical error in any site characterisation parameter for any set of wave, current and turbulence conditions. Results of the model validation using the VDCP show that the tidal flow model, and in particular the newly developed wave-current interaction module, is effective in simulating field subsurface velocities over a range of depths, for waves of up to 3m significant wave height and currents of up to 3.5ms-1. The model is effective in reproducing the wave climate using both measured and modelled surface elevation spectra, and tests, with marginal improvements, the effect of modifying the dispersion equation to account for currents. Field and model velocities compare well over the frequency range dominated by waves, showing only small underestimations in model standard deviations with respect to those from field data, at depths close to the sea surface. At the low frequency end of the modelled spectra, where large turbulent eddies dominate, there is some deviation in model accuracy, particularly during the ebb tide where recorded turbulence parameters are extremely variable, creating uncertainty due to a relatively small sample size. Between field and model velocity maxima, some scatter is observed, potentially providing uncertainty in the estimation of ultimate loads. Model and field damage equivalent velocities, used in the determination of fatigue loads, agree well. Results suggest that a linear wave-current representation of subsurface velocities at this particular tidal site is applicable. Care should be taken when interpreting this result due to the relatively small sample size, and the possibility of site specific nuances, and as such further studies are proposed. The Virtual DCP model is a novel development which has proven its usefulness in the work contained in this thesis and in the analysis of commercial field data. It is extremely versatile, adapting to a range of configurations and set up criteria such that it can be used in the quantification of DCP measurement error for a range of flow characteristics. This information is useful in the design of tidal turbines (and other sub-sea structures) as well as for oceanographic and biological processes. The tidal flow model developed extends beyond the capability of similar numerical models with the capability to model the interaction between waves and currents according to a number of different options. Combined with the VDCP, which samples from the model flow field, a system is created that can be effectively calibrated to find the best model solution to replicate flows at a tidal site measured by a 'real' DCP over a broad range of sea conditions and water depths. The purpose is to ensure that models used to predict the sub surface velocities in the field are suitable and a key question was to understand whether the linear super-position of linear wave models and a turbulent current flow provides a realistic model of the particle kinematics with a view to undertaking loads analysis of a tidal stream turbine. Comparisons of this kind have not previously been documented, and this thesis lays out the path to improved site characterisation.
26
Yu, Chunshui. "Two Dimensional Finite Volume Model for Simulating Unsteady Turbulent Flow and Sediment Transport." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/301662.
Анотація:
The two-dimensional depth-averaged shallow water equations have attracted considerable attentions as a practical way to solve flows with free surface. Compared to three-dimensional Navier-Stokes equations, the shallow water equations give essentially the same results at much lower cost. Solving the shallow water equations by the Godunov-type finite volume method is a newly emerging area. The Godunov-type finite volume method is good at capturing the discontinuous fronts in numerical solutions. This makes the method suitable for solving the system of shallow water equations. In this dissertation, both the shallow water equations and the Godunov-type finite volume method are described in detail. A new surface flow routing method is proposed in the dissertation. The method does not limit the shallow water equations to open channels but extends the shallow water equations to the whole domain. Results show that the new routing method is a promising method for prediction of watershed runoff. The method is also applied to turbulence modeling of free surface flow. The κ - ε turbulence model is incorporated into the system of shallow water equations. The outcomes prove that the turbulence modeling is necessary for calculation of free surface flow. At last part of the dissertation, a total load sediment transport model is described and the model is tested against 1D and 2D laboratory experiments. In summary, the proposed numerical method shows good potential in solving free surface flow problems. And future development will be focusing on river meandering simulation, non-equilibrium sediment transport and surface flow - subsurface flow interaction.
27
Walker, James William Civil & Environmental Engineering Faculty of Engineering UNSW. "The exchange of oxygen at the surface of open waters under wind forcing." Publisher:University of New South Wales. Civil & Environmental Engineering, 2009. http://handle.unsw.edu.au/1959.4/43712.
Анотація:
A series of detailed laboratory investigations were conducted to examine low solubility gas transfer across wind-forced wavy air-water interfaces. The study focuses on the increase in gas flux associated with the microphysical interfacial wind momentum exchange and the complex wave coupled hydrodynamics. Key elements of the laboratory investigations included the measurement of hydrodynamic behaviour within the aqueous viscous sub-layer using a particle image velocimetry (PIV) system and the development of a Laser Induced Fluorescent (LIF) system capable of measuring reliable dissolved oxygen concentration profiles to within 28??m of the air-water interface. Major achievements and findings included: 1. The first phase resolved gas flux measurements along wind forced microscale waves, indicating the highest mean gas fluxes are located in the wave troughs. This finding demonstrated the relative importance of wave orbital straining in gas flux enhancement; a wave coupled hydrodynamic process whose significance has previously been neglected. 2. The relative contributions to gas flux from wind shear, wave orbital straining, increased surface area of the waves, parasitic capillary ripples and microscale breaking are quantified with respect to friction velocity, wave steepness and an efficiency of microscale wave breaking. The parasitic capillary ripples are shown to have a negligible role in gas enhancement. A hybrid model is developed to estimate the gas flux based on both wind and wave characteristics. 3. Gas enhancement due to microscale wave breaking and the significance of the highly localised subduction at the toe of the spilling region on the leeward face of the wave crests was investigated using data from the LIF experiments. The highly localised subduction was shown to substantially reduce the thickness of the diffusion sub-layer, resulting in an increase in gas flux when waves transitioned from the incipient breaking to the microscale breaking wave form. 4. Consideration of previously unidentified optical distortions in LIF imagery due to non-linear effects is presented that is critical for robust LIF data processing and experimental design. A formal mathematical description of optical distortions has been developed and presented.
28
Ben, Souf Mohamed Amine. "Approche stochastique à base de modes d'ondes : théorie et applications en moyennes et hautes fréquences." Thesis, Ecully, Ecole centrale de Lyon, 2012. http://www.theses.fr/2012ECDL0035/document.
Анотація:
Ce travail de recherche a été réalisé au sein du Laboratoire de Tribologie et Dynamique des Systèmes de l’École Centrale de Lyon (FRANCE) en cotutelle avec l’Unité de Mécanique, Modélisation et Productique (U2MP) à l’École Nationale d’Ingénieurs de Sfax (TUNISIE) dans le cadre du projet européen "Mid-Frequency". La prédiction du comportement dynamique des structures est une tâche importante dans la phase de conception de tout produit mécanique. Le choix de l’outil ou de la méthode utilisée dépend de plusieurs facteurs. Pour un système dynamique, la bande de fréquence d’étude est l’un des paramètres essentiels étant donné qu’il existe des approches appropriées pour chaque domaine fréquentiel. Ces derniers seront rapidement inapplicables en changeant le domaine d’application. Par exemple, les méthodes dites hautes fréquences ou globales sont très limitées dans la partie basse du spectre. De même, les méthodes dites basses fréquences deviennent, numériquement, très lourdes et peu performantes si l’on monte en fréquence. Les moyennes fréquences représentent alors les hautes fréquences pour les méthodes globales et les basses fréquences pour les méthodes locales. Comme les incertitudes jouent un rôle important dans les comportements vibratoires en moyennes fréquences, le travail présenté de ce mémoire est une contribution à la recherche d’une approche peu coûteuse en temps de calcul permettant l’extension d’une méthode locale : la méthode des éléments finis ondulatoires, à cette bande de fréquence pour les systèmes à caractère non déterministe. Cette contribution consiste à tenir compte des incertitudes présentes dans le système étudié pour évaluer la dispersion des différents paramètres (spectraux, de diffusion, dynamiques, etc.) et leurs effets sur la réponse globale (cinématique et énergétique) de la structure. Le travail présenté peut être partagé en deux parties. La première concerne le développement des formulations explicites et directes des dispersions des différents paramètres. Cette partie se base sur l’utilisation de la méthode de perturbation à l’ordre un. La deuxième partie est une généralisation de la première. En effet, l’utilisant de la projection des variables aléatoires sur la base des polynômes de chaos permet une évaluation plus générale des effets des incertitudes sur la dynamique des structures périodiques en moyennes fréquencesThe prediction of dynamic behavior of structures is an important task in the design step of any mechanical product. There are many factors affecting the choice of the used methods. For a dynamic system, the frequency band under study is one of the important parameters since for each frequency range exists its appropriate approach which can be quickly inapplicable in other domains. For example, the high frequency methods are very limited in the lower part of the spectrum. Similarly, the so-called low-frequency methods become numerically inefficient if it goes up in frequency range. The mid-frequencies then represent the high-frequencies for global and low frequencies for local methods. Knowing that uncertainties play an important role on the vibro-acoustics behavior in mid-frequencies, the presented work is a contribution to the research approach, with inexpensive computing time, allowing the extension of a local method, called ’the wave finite element method’, in this frequency band. These contributions consist in taking into account uncertainties in the studied system to evaluate the dispersion of all parameters (spectral, diffusion, dynamics, etc.) and their effects on the global response (kinematic and energetic) of the structure. The presented work can be divided into two main parts. The first one involves the development of an explicit and direct formulation describing the dispersion of different parameters; this part is based on the first-order perturbation method. The second part is a generalization of the first one; indeed, using the chaos polynomial projection of all random variables allows a more general assessment of the effects of uncertainties on the dynamics of periodic structure in mid-frequency range
29
Philipp, Andy. "Novel Analytical Hydrodynamic Modeling for Evaluating and Optimizing Alluvial Recharge." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-124891.
Анотація:
This thesis presents a novel analytical solution strategy for the zero-inertia (ZI) equations of free surface flow. These equations are utilized herein for routing flood flow in open channels and for simulating excess rainfall runoff on overland planes. The novel solution approach is shown to be both accurate and robust, especially under the complicated and intricate conditions of infiltrating flow on initially dry river beds or soils, e.g., as present in arid and semiarid areas. This is underlain by comparing modeling results of the novel analytical procedure with those of validated numerical solutions. Furthermore, it is shown that the analytical ZI model can deliver a process-oriented portrayal of runoff concentration in the flood-generating parts of the catchment. Subsequently, the novel analytical ZI model is applied for a real-world water management problem in the Sultanate of Oman, Arabian Peninsula. Within an integrated flash flood routing model—which is also presented in this thesis—the novel analytical routing approach helps in accurately matching the dynamics of advancing and infiltrating ephemeral river flow, established as a consequence of release from a groundwater recharge dam. The integrated modeling system houses the aforementioned analytical downstream model and tailor-made, state-of-the-art modeling components to portray the upstream flow processes, dam operation (including evaporation), and spillway release flow. The proposed modeling system can aid in rendering a realistic image of transient transmission losses and dependent flow dynamics. This is of extremely high importance for water resources assessment, as well as for optimizing recharge dam operation strategies in order to maximize downstream transmission losses and, thus, groundwater rechargeDiese Dissertation präsentiert einen neuartigen analytischen Lösungsansatz für das beschleunigungsfreie Wellenmodell (bzw. „Zero-Inertia-Modell“, „ZI-Modell“, oder „diffusives Wellenmodell“). Im Rahmen der Arbeit wird das hergeleitete hydrodynamische Modell sowohl zur Simulation von Freispiegelabflüssen in nichtprismatischen und durchlässigen Gerinnen, als auch für die Beschreibung von auf der Landoberfläche abfließendem Infiltrationsüberschuss eingesetzt. Es wird gezeigt, dass der neuartige analytische Ansatz — im Hinblick auf Massenerhaltung und die exakte Abbildung der Abflussdynamik — akkurate Ergebnisse liefert und gleichzeitig unter komplexen und verwickelten Prozessbedingungen anwendbar ist. So belegt eine vergleichende Analyse mit validierten numerischen Lösungsansätzen die Robustheit des analytischen ZI-Modells. Insbesondere die im Sinne der numerischen Mathematik stabile und genaue Modellierung der gekoppelten Abfluss- und Infiltrationsvorgänge in anfänglich trockenen Gerinnen ist dabei ein Novum. Weiterhin wird die Eignung und Anwendbarkeit des neuartigen Modellansatzes zur Beschreibung der Abflusskonzentrationsprozesse gezeigt. Der neuartige Lösungsansatz wird im Folgenden für ein reales Wassermanagementproblem im Sultanat Oman, Arabische Halbinsel eingesetzt. Als Bestandteil eines integrierten Modellsystems, welches ebenfalls im Rahmen der Dissertation vorgestellt wird, dient das analytische ZI-Modell zur Simulation von infiltrierendem Wadiabfluss, welcher unterstrom von Grundwasseranreicherungsdämmen starke Verluste von Masse und Impuls erfährt. Zusammen mit maßgeschneiderten und dem Stand der Technik entsprechenden Komponenten für die Betriebssimulation des Anreicherungsdammes (inklusive Verdunstung von der freien Seefläche) sowie für die Abbildung der oberstromigen hydrodynamischen Prozesse (ebenfalls inklusive Infiltration) wird der neuartige analytische Ansatz in einem Modellsystem zusammengefasst. Das Modellsystem ist in der Lage ein realistisches Bild der raumzeitlichen Dynamik des Abflusses sowie der Grundwasserneubildung aus infiltrierendem Wadiabfluss zu liefern. Damit stellt das Modellsystem ein wertvolles Werkzeug sowohl zur Wasserdargebotsermittlung, als auch für die Optimierung des Betriebes von Grundwasseranreicherungsdämmen dar
30
Mikulik, Petr. "Réflectivité des rayons X par des multicouches planaires et structurées." Université Joseph Fourier (Grenoble), 1997. http://www.theses.fr/1997GRE10056.
Анотація:
La reflectivite des rayons x par des multicouches planaires et structurees est presentee en utilisant differentes approches theoriques. Les phenomenes de diffusion etudies sont : la reflectivite speculaire par des multicouches planaires ayant diverses sequences d'empilement (monocouche, periodique, quasiperiodique), la diffusion diffuse de multicouches rugueuses, et enfin la diffusion par des reseaux de surface et par des reseaux de multicouche. Les theories employees pour les calculs : la theorie cinematique, l'approximation de l'onde deformee de born, la theorie dynamique, et plusieurs approximations de la theorie dynamique (approximation a une reflexion unique, approximation a deux ondes et approximation a diffusion multiple), sont developpees dans un formularisme unique. Ce formalisme permet de discuter et de comparer toutes les theories d'une maniere solide et methodologique. Les calculs numeriques sont appliques pour l'ajustement des courbes experiementales pour mettre en evidence les parametres structuraux des divers systemes multicouches.
31
Murphy, Shane. "A dynamic and kinematic investigation of early rupture waves and their seismic radiation." Tesi di dottorato, 2008. http://www.fedoa.unina.it/1897/1/Murphy_Rischio_Sismico.pdf.
32
Bai, Chao-Ying. "Three dimensional seismic kinematic inversion with application to reconstruction of the velocity structure of Rabaul volcano / by Chao-ying Bai." 2004. http://hdl.handle.net/2440/22132.
Анотація:
"July 2004"Bibliography: leaves 215-230.
viii, 230 leaves : ill., maps ; 30 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Thesis (Ph.D.)--University of Adelaide, School of Chemistry and Physics, Discipline of Physics, 2004
33
Bai, Chao-ying. "Three dimensional seismic kinematic inversion with application to reconstruction of the velocity structure of Rabaul volcano / by Chao-ying Bai." Thesis, 2004. http://hdl.handle.net/2440/22132.
34
"Comparative studies between the kinematic and diffusive waves on the flood routing analisys, in function of hydraulics parameters of the watershed." Tese, Biblioteca Digital de Teses e Dissertações da UFC, 2006. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=242.
35
Stempinski, Florian [Verfasser]. "On wave kinematics in harsh seaway an freak waves / vorgelegt von Florian Stempinski." 2009. http://d-nb.info/995984344/34.
36
Chang, Chin-Hsin, and 張進鑫. "Flood Frequency Analysis based on Kinematic wave theory." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/72496770093699274776.
37
LU, ZHEN-MO, and 呂珍謀. "Kinematis wave and diffusion wave routing models for upstream catchment runoff." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/36240046932949779117.
Анотація:
博士國立臺灣大學
土木工程研究所
78
In this study, the τ-s two parameter characteristics method (τ is the c- haracteristics curve and s is the time value which follows the characteri- stics curve) is used to solve the kinematic wave equations for runoff rou- ting. Using this approach, the problem of numerical stability and the siz- es of △x and △t, which affecting the truncating errors in finite differ- ence method, can be easily handled. The hydrograph at any position and wa- ter profiles at any time instand can be calculated effectively. The diffusion wave model has been applied to the channel downstream of the catchment. The cross section of the channel is assumed to be triangle, and a nondimensional equation governing diffusion wave movement in the channel is derived. Solving this equation by variable seperation and weighted res- idual methods, the numerical results are obtained. There are two advantag- es of this approach: (i) Variables x and t can be arbitrary chosen without any error. These errors are normally induced by selecting △x and △t, if a finite difference scheme is used. (ii)Only simple schemes such as Newton iteration and Runge-Kutta methods are needed. For practical application, t- hese advantage are most useful. To test the models proposed,flood hindcastingshave been madeonthe Japanese Tatsunokuchiyama,Pi Lu Chi No.11 experimental catchment and the PaiHo res- ervoir catchment.In these tests,the input hyetographs are discrete time f- unctions,the routing processes in a time interval are linear,and the outl- et hydrographs are linear superposition of the hydrographs during the per- iodof rainfall. The results calculated from kinematic wave and diffusion wave models show good agreement with the observed flood records. Other main conclusions can be drawn: (1) In the runoff routing models for upstream catchment, the main factor affecting the runoff is the geographical conditions of slope.The roughness factor of channel as indicated in the appendix G is not a senitive parame- ter. (2)Both the kinematic wave model and diffusion catchment.However,it is pr- eferable to use the diffusion wave model for the sake of safety. For a ca- tchment of moderate size, the dependence of the Chezy''s coefficient on ro- utingis apprarently increased, and if the C value can not be ascertain, it wouldbe more appropriate to use the kinematic wave model in order to avoid unnecessary errors.
38
Hu, Shiou-Hua, and 胡修華. "Developing Block Kinematic Wave Model for Direct Runoff Hydrograph Estimate." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/08257560500902880902.
Анотація:
碩士國立臺灣大學
土木工程學研究所
99
Open channel hydraulics show that the main factor determining discharge of a long channel is the water depth (or storage) near the channel exit, not the rainfall intensity on the river, not the upstream inflow. The later two factors affect discharge by increasing or decreasing storage. However, unit hydrograph (UH) and other traditional black-box rainfall-runoff models assume direct runoff respond linearly to excess rainfall intensity. The effect of storage within the watershed is not considered in UH, and the linear assumption does not really valid in a watershed. Estimation error maybe large if rainfall intensity varies significantly within a catchment’s time of concentration (which is a function of rainfall intensity too), or when the average rainfall intensity used to create UH is very different from that using UH to estimate runoff hydrograph. In recent years, Digital Elevation Model and GIS make possible to construct a watershed’s runoff flow path network. Apply Kinematic Wave (KW) model to compute the flow speed on the flow paths, runoff hydrograph can be calculated without using linear assumption. The KW model computation is time-consuming. When KW is applied to flood forecast, the state variables of each link must be saved at the end of one forecast and retrieved at the beginning of next. Numerical problems may occur applying the essentially steady-state KW model to rapidly varying hyetograph. The numerical problem is more serious at the upstream flow paths where the channel storages are less. We propose a rainfall-runoff model called Block Kinematic Wave (BKW). It does not apply the linear assumption, and it does not have the numerical problem of KW. It’s algorithm follows. First, apply the ArcInfo geographic information system and HEC GeoHMS tool module to construct the 40-meter resolution flow paths and river network. Then, compute the Topographic Index (TI) of each flow path. Thirdly, utilize TI to parameterize the cross-section and Manning’s n of each flow path. Fourth, assume different excess rainfall intensity and compute the travel time (TT) of all pixels to watershed exit for all intensities. Fifth, divide the catchment into several equal area blocks, handle the pixels go across block boundaries at different rainfall intensities. Sixth, calculate the storage on each flow path and total the flow path storage, S, of a block given an effective rainfall intensity. Also, compute the total discharge at all block boundaries, Q. Construct the storage – discharge relationship for each block using all different steady-state excess rainfall intensity results. Seventh, compute the direct runoff from each block using reservoir routing. That is using continuity equation and S-Q relationship. By doing so, the discharge from a block is mainly determined by its storage. Here, excess rainfall intensity is only one of the inputs to the block storage. The BKW model uses steady state rainfall intensities to construct the S-Q relationship for each block. No linear assumption is involved. The BKW model does not suffer the numerical problem of KW given non-constant hyetograph because it uses KW for steady-state computation only. The BKW model for direct runoff is computationally very efficient, because most of the calculations are pr-processed and carried out offline. There are only a few reservoir routing computations to be executed online. With these three nice properties, BKW model is especially suitable to calculate direct runoff hydrograph within Taiwan''s flash flood forecast system. Observing Systerm Experiments are designed to compare the performances of BKW. A Muskingum-Cunge based flow-path computation model is assumed to produce the “true direct runoff hydrograph” from a watershed. BKW model is then validated with some other “the true direct runoff hydrographs”. Computation time of BKW and the “True” model are also compared.
39
Lim, Ho Joon. "Experimental Study on Kinematics and Dynamics of Breaking Waves in Deep Water." Thesis, 2010. http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8501.
Анотація:
A new measurement technique called fiber optic reflectometer (FOR) was
developed to investigate multiphase flows. The principle and setup of the FOR technique
were introduced and applied to various experiments. Based on the coherently mixed
signal between the Fresnel reflection off the fiber-liquid interface and the scattered
signal off the object, such as a gas bubble, and a solid particle, this single probe
technique is capable of simultaneously measuring the velocity of the object with a high
accuracy and the phase of the fluid. In addition, bubble diameter, velocity, and void
fraction were measured directly.
By means of a simple modification of the FOR technique, solute concentration and
refractive index change were measured with a greatly improved accuracy. This modified
technique was used for measuring of a NaCl concentration in deionized water to validate
a new normalization technique.
In the second part of this thesis, a plunging breaking wave in deep water has been
studied. Using the wave focusing method, a strong plunging breaker was generated with
accuracy in the deep water condition in a two-dimensional wave tank. It was possible to
describe the breaking process in detail using a high speed camera with a frame rate of 500 or 1000 fps.
Four kinds of experimental techniques were employed or developed to investigate
the plunging breaker. Bubble image velocimetry (BIV) and particle image velocimetry
(PIV) were used to measure the velocity fields. The velocity fields of the highly aerated
region were obtained from the BIV measurements. In addition, the modified PIV
technique is capable of measuring the velocities in the entire flow field including the
aerated region. Mean and turbulent properties were obtained by the ensemble average.
The mean velocity, mean vorticity, and mean kinetic energy were examined over the
entire flow field. In addition, the Reynolds stresses and turbulent kinetic energy were
calculated with high temporal and spatial resolutions. Free surface elevation was
obtained from wave gauge measurements. BIV and PIV images were also used to obtain
the free surface elevation and the boundary of the aerated region for more accurate
results.
The FOR technique was used to obtain the void ratio at each splash-up region.
Compressibility of the plunging breaker was considered. Mass flux, momentum flux,
kinetic energy, and Reynolds stresses at each FOR station were recalculated using the
void ratio obtained from the FOR measurements. All terms at the first splash-up region
were highly overestimated more than 100 percent unless the void ratio was applied to the
calculation of fluxes and energies. Compared with the fully developed first splash-up
region, the overestimation at the second and third splash-up was less significant.
However, most terms were overestimated by 20~30 percent when the void ratio was not
considered.
40
Lu, Hsiu-Chen, and 盧綉真. "Influences of rainfall patterns and infiltration on kinematic wave overland flow." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/10079777565388312857.
Анотація:
碩士國立交通大學
土木工程系所
93
In this study, based on one-dimensional kinematic wave overland flow theory and Green-Ampt infiltration theory, the effects of rainfall patterns and infiltration on overland flow are examined. First, four hypothetical rainfall patterns, including uniform, delayed, advanced, and intermediate rainfall patterns, in temporal distribution are used to conduct this examination. The moving storm with different rainfall patterns in spatial distribution is then applied to further investigations. The results show that the overland flow is significantly related to the rainfall patterns and infiltration. The delayed rainfall pattern produces larger peak discharge with the latest occurrence than the other three ones. The peak discharge of the uniform rainfall pattern is largely underestimated as compared with the other three rainfall patterns. For the advanced rainfall pattern, the time to peak discharge is shorter than those of the others. In addition, the infiltration could not only decrease the discharge but also affect the runoff pattern of overland flow.
41
Chung, Wen-Chung, and 鍾文忠. "An Error Analysis Study on Block Kinematic Wave Direct Runoff Model." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/41000781813307372115.
42
Arun, K. R. "Kinematical Conservation Laws And Propagation Of Nonlinear Waves In Three Dimensions." Thesis, 2010. https://etd.iisc.ac.in/handle/2005/1917.
43
Arun, K. R. "Kinematical Conservation Laws And Propagation Of Nonlinear Waves In Three Dimensions." Thesis, 2010. http://hdl.handle.net/2005/1917.
44
Swigler, David Townley. "Laboratory Study Investigating the Three-dimensional Turbulence and Kinematic Properties Associated with a Breaking Solitary Wave." 2009. http://hdl.handle.net/1969.1/ETD-TAMU-2009-08-821.
Анотація:
A laboratory experiment was performed to investigate the three-dimensional turbulence and kinematic properties that develop due to a breaking solitary and an irregular shallow water bathymetry. A large basin equipped with a piston-type wavemaker was used to generate the wave, while the free surface elevations and fluid velocities were measured using wave gauges and three-dimensional acoustic-Doppler velocimeters (ADVs), respectively. From the free surface elevations, the evolution and runup of the wave was revealed; while from the ADVs, the velocity and turbulent energy was determined to identify specific turbulent events and coherent structures.
It was found that shoaling was confined to areas with gentler sloping bathymetry near the basin side walls and the runup shoreward of the still water shoreline was not uniform. The runup was characterized by a jetting mechanism caused by the convergence of water mass near the basin centerline as the wave refracted during breaking. The jetting mechanism caused the greatest cross-shore velocities to be located near the basin centerline. The greatest turbulent events were well correlated to borefronts, resembling hydraulic jumps, where the greatest shear and fluid accelerations occurred. Because of an abrupt change in the bathymetry, a coherent structure developed which was found to have a three-dimensional flow field. It was proposed that variations in the internal flow with depth were due to the orientation of multiple vortex rings.
45
TSOU, MING-SHU, and 鄒明樹. "Re-evaluation of rational method using kinematic wave approach in slopeland community." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/41878945072174973688.
46
HONG, YAO-MING, and 洪耀明. "Application of remote sensing and geographic information system for kinematic wave-flood routing." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/58674715680675487512.
47
Liao, Xin-yue, and 廖欣岳. "Experimental Studies on Kinematic Characteristics of Wave-Fluidized Bed Interactions near above the Bed." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/94296748205881949040.
Анотація:
碩士國立成功大學
水利及海洋工程學系碩博士班
95
In this study, the interactions of nonlinear waves and a wave-fluidized fine sandy bed (d50=0.073mm) are investigated by flume experiments. Experimental results illustrate that relative water depth in a fluidized response is very important to wave decay, pore pressure dissipation, resonance amplification and bed displacement. With larger wave-induced pore pressure oscillations, the resultant fluidized-layer depth becomes deeper and causes increasing amplitudes of bed’s oscillating displacements. In particular, the same peak frequencies of bed’s displacement as those of the loading waves suggest the forced motions of the fluidized bed by surface waves. Accompanying the bed’s displacements in a fluidized response, near-bed fluid velocity fields are noted to be evidently changed while suspended sediment concentrations are significantly increased. In addition, the longer cycles of sediment concentration seems to be related with both bed and wave motions. According to frequency spectrum, nonlinear effects appear not only on surface waves, but also on bed’s fluidized responses including pore pressure oscillation, bed displacement, and the fluid velocity fields. Even if waves occur to decay, the decay rate is mainly on the peak frequency while the super-harmonic components remain evident in the near-bed fluid velocity fields. This further complicates the interactions of waves and a fluidized bed. In the end, wave data from former studies with different bed’s particle diameter have been collected to determine the regress lines (relative water depth, wave steepness) for generating resonant fluidization. These regress lines could perform quite well for estimating the wave conditions for a fluidized response so that the mechanism of fluidized layers and bed displacements in a resonant response could be studied in more detail.
48
Wu, Chung-Ming, and 巫仲明. "Analytical Runoff Simulation Using The Kinematic Wave Characteristic Method Under Single Unsteady Rainfall Event." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/53313882449731047288.
Анотація:
博士國立中興大學
水土保持學系
91
The aim of this study is to apply the characteristic method to the kinematic wave overland flow model under different types of lateral inflow. There are five types of lateral inflow under the following conditions: A1: under steady-uniform rainfall using the index method minus rainfall loss, A2: under steady-uniform rainfall combing the constant infiltration rate method, A3: under steady-uniform rainfall using Philip’s equation to model rainfall excess, B1: under unsteady rainfall event using the index method minus rainfall loss, B2: under unsteady rainfall event combing the constant infiltration rate method. This study is to verify the-above-mentioned models by using three types of techniques including: 1.The first type is to verify A1 on the different roughness of laboratory overland flow experiments under the artificial rainfall condition. 2.The second type is to verify A3 under the same conditions as the previous researches. 3.The third type is to verify B2 by using the data of discharge hydrographs of erosion experiment plots of overland flow in china fir plantations and betel-net plantations. From the laboratory and the field overland flow experiments, the relative error of the modeled value and the observed value of runoff discharge is 0.1~0.27; the exactness and the applicability in this study are significant.
49
Hsu, Chih-Yang, and 許志揚. "The Estimation of Watershed Design Discharge Based on Kinematic Wave Theory and Rational Method." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/21552826733800275121.
50
Xu, Zhi-Yang, and 許志揚. "The Estimation of Watershed Design Discharge Based on Kinematic Wave Theory and Rational Method." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/89941644001720233342.