Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 122 for “"wave field"”.
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Dynamics of an oil containment boom in a wave field.
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1970.
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Direct simulation and deterministic prediction of large-scale nonlinear ocean wave-field
… approximation of physics, the phase-averaged wave spectrum model has been the only type of tool available for ocean wave prediction in the past 60 years. With the rapid advances in sensing technology, phase-resolved nonlinear wave modeling, and high performance computing capability in recent …
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Determination of directional spectra of sea surface wave field by scanning observation.
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1972.
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The rise and dilution of buoyant jets and their behaviour in an internal wave field
… and the effects of high-frequency internal waves on the motion of the buoyant jet. Past buoyant jet models were constructed for specific cases and their application is necessarily restricted. In this thesis, a new model is developed in a Lagrangian framework that can be applied to buoyant …
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Phase-resolved reconstruction and forecast of nonlinear irregular wave field based on direct numerical simulations
… reconstruction and forecast of ocean wave field based on measurements is of basic scientific interest and practical importance in ocean science and marine engineering. This capability aids and expands the use and interpretation of field and wave basin measurements, contributing to the …
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A study of ocean wave statistical properties using nonlinear, directional, phase-resolved ocean wave-field simulations
In the present work, we study the statistics of wavefields obtained from non-linear phase-resolved simulations. The numerical model used to generate the waves models wave-wave interactions based on the fully non-linear Zakharov equations. We vary the simulated wavefield's input spectral properties: …
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Characterization of nonlinearity parameters in an elastic material with quadratic nonlinearity with a complex wave field
This research investigates wave propagation in an elastic half-space with a quadratic nonlinearity in its stress-strain relationship. Different boundary conditions on the surface are considered that result in both one- and two-dimensional wave propagation problems. The goal of the research is to …
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A study of ocean wave statistical properties using nonlinear, directional, phase-resolved ocean wave-field simulations
In the present work, we study the statistics of wavefields obtained from non-linear phase-resolved simulations. The numerical model used to generate the waves models wave-wave interactions based on the fully non-linear Zakharov equations. We vary the simulated wavefield's input spectral properties: …
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Acoustic travel time perturbations due to an internal tide and internal wave field in the Barents Sea
… modes due to an internal tide and internal mode field in the Barents Sea are examined. A formalism for the travel time perturbation due to a change in sound speed is presented. Internal tide and internal wave amplitude spectra are calculated from Brancker temperature loggers which were deployed …
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STRATIFIED WAKE SIGNATURES GENERATED BY PROPAGATING SUBMERGED BODIES IN THE PRESENCE OF AN ACTIVE INTERNAL WAVE FIELD
… wake in the presence of background internal waves using numerical simulations. To achieve this, we conducted numerical simulations on Department of Defense high-performance computing systems using the Massachusetts Institute of Technology general circulation model, which we adapted for wake …
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Sea surface wave reconstruction from marine radar images
… being increasingly used to measure sea surface waves nowadays. In this thesis, how to reconstruct sea surface wave elevation maps from X-band marine radar images and do wave field prediction over short term in real time are discussed. The key idea of reconstruction is using dispersion relation …
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Simulation of High Frequency Waves Reflected From a Turbulent Ionosphere for Spread Spectrum Systems
The communication channel established with HF waves reflected by the ionosphere is investigated. The background ionosphere is modeled by a horizontally stratified medium. This model is superimposed with random irregularities. The resulting channel is characterized by a random transfer function. …
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Experimental investigation of 2D and 3D internal wave fields
The generation of 2D and 3D internal wave fields is extensively studied via planarand stereo- Particle Image Velocimetry (PIV) flow field measurement techniques. A benchmark was provided by an experiment involving tidal flow over a 2D Gaussian ridge; this study providing a counterpart with which …
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Visualizing internal wave generation by finite cylinder oscillations using stereo particle image velocimetry
This thesis investigates internal wave generation in a stratified fluid by means of an oscillating cylinder. We observe the consequences of boundary effects by the production of an out-of-plane velocity field as the cylinder span is decreased. Four cylinders are used. Stereoscopic PIV is utilized …
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Analysis and design of wave scattering by weakly non-uniform waveguides
When waves propagate through a medium with small irregularities of the size of the order of many wavelengths, a number of interesting phenomena may happen such as wave localization and large sensitivity of the wave field behavior with respect to the medium irregularity variation. These phenomena …
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Interpretation of equatorial current meter data as internal waves
… Munk use linear dynamics to synthesize frequency-wavenumber energy spectra for internal waves (GM72, GM75, GM79). The GM internal wave models are horizontally isotropic, vertically symmetric, purely propagating, and universal in both time and space. This set of properties effectively eliminates …
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Ultracold quantum gases in three-dimensional optical lattice potentials
… optical lattice potential formed by a standing wave laser light field. In this novel quantum system we have been able to both realize a quantum phase transition from a superfluid to a Mott insulator, and to observe the collapse and revival of a macroscopic matter wave field. Quantum phase …
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Laboratory scale experiments with water surface waves
… small scale, for the study of surface gravity waves. A number of measurement techniques are developed and implemented to capture space and time evolution of waves on a water surface in gravity, gravity-capillary and capillary ranges with the purpose to study the statistics of wave turbulence in …
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Emission of whistler waves from an ionospheric tether
In this thesis, we analyze how electromagnetic waves propagate in ionosphere around the earth which is magnetized plasma. We calculate the electromagnetic wave field made by a dipole antenna at an arbitrary observation point far from the antenna using the Stationary Phase Method. With this wave …
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Improvements in the numerical modelling of wake effects for wave energy converter farms
… estimated that 100 GW of ocean energy capacity (wave and tidal) could be deployed in Europe by 2050. Along with these European targets it is expected that large farms of Wave Energy Converters (WECs) will be installed in the sea and as part of the consenting process it will be necessary to …
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