A nonlinear wave equation is developed, modeling the evolution in time of shallow water waves over a variable topography. As the usual assumptions of a perfect fluid and an irrotational flow are not made, the resulting model equation is dissipative due to the presence of a viscous boundary layer at...
Numerical solutions of the Korteweg-de Vries (KdV) and extended Korteweg-de Vries (eKdV) equations are used to model the transformation of a sinusoidal internal tide as it propagates across the continental shelf. The ocean is idealized as being a two-layer fluid, justified by the fact that most of the oceanic internal...
We will consider the implementation of a computer program to
solve a nonlinear algebraic system of N equations and unknowns.
The program involves the use of a parameter, Newton's method, and
an automatic change of parameter. Also considered are rigorous
error bounds for the answer. The program was implemented and...
A perfectly matched layer (PML) is widely used to model many different types of wave propagation in different media. It has been found that a PML is often very effective and also easy to set, but still many questions remain.
We introduce a new formulation from regularizing the classical Un-Split...
In this paper, Fourier analysis is used to
investigate various approximation methods for the one- and
two-dimensional wave equations. The spatial derivatives
are approximated by the second order centered finite
difference method, the linear and quadratic finite element
methods, and the fourth order centered finite difference
method. The approximation schemes...
Stochastic analysis procedures have been recently applied to analyze nonlinear
dynamical systems. In this study, nonlinear responses, stochastic and/or chaotic, are
examined and interpreted from a probabilistic perspective. A multi-point-moored
ocean structural system under regular and irregular wave excitations is analytically
examined via a generalized stochastic Melnikov function and Markov...
In 1974 Davey and Stewartson used a multi-scale analysis to derive a coupled
system of nonlinear partial differential equations which describes the evolution of a
three dimensional wave packet in water of a finite depth. This system of equations
is the closest integrable two dimensional analog of the well-known one...
In this dissertation, we investigate three numerical methods for inverting the Laplace transform. These methods are all based on the trapezoidal-type approximations to the Bromwich integral. The first method is the direct integration method: It is a straightforward application of the trapezoidal rule to the Bromwich integral, followed by convergence...
The fractal dimension of measured ocean wave profiles is found to be in the range of 1.5-1.8. This non-integer dimension indicates the fractal nature of the waves. Standard formulations to analyze waves are based on a differential approach. Since fractals are non-differentiable, this formulation fails for waves with fractal characteristics....
The two dimensional wavemaker problem on a finite domain is derived
for nonlinear waves. A numerical method based on the method of lines is
developed and applied to two test problems, the nonlinear surface pressure
distribution problem and the nonlinear full-flap wavemaker problem. The
solutions yield information about the fluid...
The properties and evolution of nonlinear internal waves (NLIWs) depend
upon the background conditions within which waves form, propagate, and dissipate. As a result, the NLIW field on the New Jersey shelf displayed dramatic variability during the Shallow Water 2006 experiment. Wave variability was exhibited by 1) amplitudes that ranged...
Arising from an investigation in Hydrodynamics, the Korteweg-de Vries equation demonstrates existence of nonlinear waves that resume their profile after interaction. In this thesis, the classical equations governing wave motion are the starting point for the development of an analogue of the KdV that describes the evolution of a wave...
The Wiggins-Holmes extension of the generalized
Melnikov method (GMM) is applied to weakly damped
parametrically excited cross waves with surface tension in
a long rectangular wave channel in order to determine if
these cross waves are chaotic. The Lagrangian density
function for surface waves with surface tension is
simplified by...
The surf zone exhibits large energetic signals from wave shoaling and subsequent dissipation due to breaking, forcing circulation. The bathymetry responds to the wave and wave-induced circulation with the growth, transport, and destruction of large scale bathymetric features, such as mega ripples and sand bars. There is an obvious fluctuation...
Accurate modeling and simulation of wave propagation in dispersive dielectrics such as water, human tissue and sand, among others, has a variety of applications. For example in medical imaging, electromagnetic waves are used to interrogate human tissue in a non-invasive manner to detect anomalies that could be cancerous. In non-destructive...
This study uses an existing database of dynamic loading tests of driven piles installed in the Puget Sound Lowlands to improve the reliability of axial performance. First, the unit shaft resistances developed from stress wave signal matching to dynamic records of pile installation are used to develop an effective stress-based...
A global solution is presented that accurately accounts for the
singular behavior at all irregular points. The linearized boundary
value problem in a semi-infinite strip in the physical plane is
transformed into a smooth unit disk by two successive conformal
mappings. The global solution results from a Fredholm integral
equation...
Shocked porous granular material experiences pressure dependent compaction. D. John
Pastine introduced a model in which the degree of compaction is dependent on the pressure induced
by the shock wave, the shear strength of the material, and the distribution of void sizes. In the
past, the model could only be...