Propagation of Waves in Shear Flows

Propagation of Waves in Shear Flows
Author: Anatoli? L?vovich Fabrikant
Publisher: World Scientific
Total Pages: 308
Release: 1998
Genre: Science
ISBN: 9789810220525

A number of well-known theorems of the hydrodynamic theory of stability are interpreted in terms of the interaction of the waves having different energy signs. Attention is drawn to the plasma-hydrodynamic analogy, which is a powerful tool for physical analyses of general mechanisms of wave amplification and absorption in flows. Various wave-flow interaction problems are considered, for instance, sound generation in whistlers, wave scattering and amplification by vortices, methods of wave remote sounding, and some nonlinear dynamical and chaotic phenomena.

Stratified Flows

Stratified Flows
Author: Chia-Shun Yih
Publisher: Elsevier
Total Pages: 439
Release: 2012-12-02
Genre: Science
ISBN: 0323150403

Stratified Flows is the second edition of the book Dynamics of Nonhomogenous Fluids. This book discusses the flow of a fluid of variable density or entropy in a gravitational field. In this edition, corrections have been made; unnecessary parts have been omitted; and new sections as well as notes on results related to the subject have been added. This book includes a general discussion of the effects of density or entropy and the structure of stratified flows; waves of small amplitude; the Eigenvalue problem; dependence of phase velocity on wavelength; wave motion; steady flows of finite amplitude; and types of solutions for steady flows. This edition also covers other topics such as hydrodynamic stability; flows in porous media; and the analogy between gravitational and electromagnetic forces. This text is recommended for those in the field of physics who would like to be familiarized with stratified flows and its related concepts.

Convection and Internal Waves in a Stably Stratified Shear Flow

Convection and Internal Waves in a Stably Stratified Shear Flow
Author:
Publisher:
Total Pages: 4
Release: 1994
Genre:
ISBN:

Wijesekera and Dillon hypothesized that internal gravity waves could be generated just below the upper ocean mixed layer as a result of convective plumes in the mixed layer. Furthermore they demonstrated that these waves could propagate downward and generate the secondary mixing events that are seen in the equatorial thermocline. We have designed a series of Large Eddy Simulations to test this hypothesis.

Internal Gravity Waves

Internal Gravity Waves
Author: Bruce R. Sutherland
Publisher: Cambridge University Press
Total Pages: 395
Release: 2010-09-02
Genre: Science
ISBN: 1316184323

The study of internal gravity waves provides many challenges: they move along interfaces as well as in fully three-dimensional space, at relatively fast temporal and small spatial scales, making them difficult to observe and resolve in weather and climate models. Solving the equations describing their evolution poses various mathematical challenges associated with singular boundary value problems and large amplitude dynamics. This book provides the first comprehensive treatment of the theory for small and large amplitude internal gravity waves. Over 120 schematics, numerical simulations and laboratory images illustrate the theory and mathematical techniques, and 130 exercises enable the reader to apply their understanding of the theory. This is an invaluable single resource for academic researchers and graduate students studying the motion of waves within the atmosphere and ocean, and also mathematicians, physicists and engineers interested in the properties of propagating, growing and breaking waves.

The Interaction of Short-wavelength Internal Waves with a Background Current

The Interaction of Short-wavelength Internal Waves with a Background Current
Author: Dave Broutman
Publisher:
Total Pages: 166
Release: 1982
Genre: Internal waves
ISBN:

Two approaches are used to explore the effects of shear on short-wavelength internal waves. In the first, the Taylor-Goldstein equation is solved exactly. The solutions reveal the inaccuracy of WKB predictions when applied to a curved velocity profile with a minimum Richardson number of order unity. To investigate internal waves in an inertial current, ray calculations are made. This second approach reveals that the process of refractive convergence, which includes the critical-layer interaction as a special case, operates at virtually all phases of the inertial oscillation and affects short waves of nearly al frequencies. It is also found, in contrast to the results of steady shear analyses, that short waves with phase speeds less that the mean flow maximum can propagate for several inertial periods without becoming unstable, and conversely that waves with initial phase speeds of two or three times the mean flow maximum can quickly become focussed to unstably high amplitudes. The final section examines the mean flow induced by three-dimensional, low-frequency, internal wave packets. Rotation alters the character of the flow so that the mean momentum is not equal to E/c, where c is the horizontal phase speed of the short waves and E is the intrinsic energy density. The generation of inertial waves by the internal wave field as found by Hasselmann (1970) for a wave field that is statistically homogeneous in the horizontal, is not predicted by a calculation that incorporates horizontal variations.