Internal waves in a horizontally inhomogeneous flow

1984 ◽  
Vol 142 ◽  
pp. 233-249 ◽  
Author(s):  
A. Ya. Basovich ◽  
L. Sh. Tsimring
Keyword(s):  
Wave Propagation ◽  
Internal Wave ◽  
Internal Waves ◽  
Short Wave ◽  
Wave Transformation ◽  
Wave Trapping ◽  
Wave Amplification ◽  
Normal Surfaces ◽  
Inhomogeneous Flow ◽  
Horizontally Inhomogeneous

The effect of horizontally inhomogeneous flows on internal wave propagation in a stratified ocean with a constant Brunt-Väisälä frequency is analysed. Dispersion characteristics of internal waves in a moving fluid and kinematics of wave packets in smoothly inhomogeneous flows are considered using wave-normal surfaces. It is shown that internal-wave blocking and short-wave transformation may occur in longitudinally inhomogeneous flows. For parallel flows internal-wave trapping is possible in the vicinity of the limiting layer where the wave frequency in the locally comoving frame of reference coincides with the Brunt-Väisälä frequency. Internal-wave trapping also takes place in jet-type flows in the vicinity of the flow-velocity maximum. WKB solutions of the equation describing internal-wave propagation in a parallel horizontally inhomogeneous flow in the linear approximation are obtained. Singular points of this equation and the related effect of internal-wave amplification (overreflection) under the action of the flow are investigated. The spectrum and the growth rate of internal-wave localized modes in a jet-type flow are obtained.

A multi-layer model for nonlinear internal wave propagation in shallow water

2012 ◽  
Vol 695 ◽  
pp. 341-365 ◽  
Author(s):  
Philip L.-F. Liu ◽  
Xiaoming Wang
Keyword(s):  
Wave Propagation ◽  
Internal Wave ◽  
Shallow Water ◽  
Internal Waves ◽  
Bottom Topography ◽  
Laboratory Data ◽  
Constant Density ◽  
Layer Model ◽  
Fluid System ◽  
Nonlinear Internal Wave

AbstractIn this paper, a multi-layer model is developed for the purpose of studying nonlinear internal wave propagation in shallow water. The methodology employed in constructing the multi-layer model is similar to that used in deriving Boussinesq-type equations for surface gravity waves. It can also be viewed as an extension of the two-layer model developed by Choi & Camassa. The multi-layer model approximates the continuous density stratification by an $N$-layer fluid system in which a constant density is assumed in each layer. This allows the model to investigate higher-mode internal waves. Furthermore, the model is capable of simulating large-amplitude internal waves up to the breaking point. However, the model is limited by the assumption that the total water depth is shallow in comparison with the wavelength of interest. Furthermore, the vertical vorticity must vanish, while the horizontal vorticity components are weak. Numerical examples for strongly nonlinear waves are compared with laboratory data and other numerical studies in a two-layer fluid system. Good agreement is observed. The generation and propagation of mode-1 and mode-2 internal waves and their interactions with bottom topography are also investigated.

scholarly journals Estimations of the nonlinear properties of the internal wave field off the Israel coast

1995 ◽  
Vol 2 (2) ◽  
pp. 80-88 ◽  
Author(s):  
E. Pelinovksy ◽  
T. Talipova ◽  
V. Ivanov
Keyword(s):  
Internal Wave ◽  
Wave Field ◽  
Internal Waves ◽  
Wave Transformation ◽  
Nonlinear Characteristics ◽  
Nonlinear Parameters ◽  
Nonlinear Properties ◽  
Parameter Estimations ◽  
Internal Wave Field ◽  
Hydrological Fields

Abstract. The measurements of the vertical structure of hydrological fields and internal waves on the Levantine Sea's polygon in the Mediterranean, obtained in the 27-th cruise of the RV "Professor Kolesnikov" in 1991, have been used to estimate the kinematic and nonlinear characteristics of the internal wave field. Statistical and spatial distributions of the vertical profiles of the Brunt-Vaisala frequency are described. They have been used to calculate the coefficients of the Korteweg - de Vries equation. This equation forms the main model for nonlinear parameters. It is shown that the variations of the long wave speed propagation and the dispersion parameter are relatively small in comparison with the variation of the nonlinear parameter. Estimations of the nonlinear properties of the internal waves, being measured, based on the calculation of the local Ursell parameter are given. This method can be used for investigation of the internal wave transformation processes in oceanic regions with horizontal variability of the hydrophysical fields (temperature, salinity) and sloped sea floor.

The coastal refraction-diffraction wave propagation model

1995 ◽  
Vol 17 (4) ◽  
pp. 6-12
Author(s):  
Nguyen Tien Dat ◽  
Dinh Van Manh ◽  
Nguyen Minh Son
Keyword(s):  
Wave Propagation ◽  
Field Data ◽  
Surf Zone ◽  
Propagation Model ◽  
Wave Transformation ◽  
Diffraction Effect ◽  
Linear Wave ◽  
Diffraction Wave ◽  
Linear Wave Propagation ◽  
Wave Propagation Model

A mathematical model on linear wave propagation toward shore is chosen and corresponding software is built. The wave transformation outside and inside the surf zone is considered including the diffraction effect. The model is tested by laboratory and field data and gave reasonables results.

An analogy between electromagnetic and internal waves

2019 ◽  
Vol 485 (4) ◽  
pp. 428-433
Author(s):  
V. G. Baydulov ◽  
P. A. Lesovskiy
Keyword(s):  
Angular Momentum ◽  
Conservation Laws ◽  
Internal Wave ◽  
Special Relativity ◽  
Internal Waves ◽  
Maxwell Equations ◽  
Wave Equations ◽  
Lagrange Function ◽  
Lorentz Transformations ◽  
Symmetry Transformations

For the symmetry group of internal-wave equations, the mechanical content of invariants and symmetry transformations is determined. The performed comparison makes it possible to construct expressions for analogs of momentum, angular momentum, energy, Lorentz transformations, and other characteristics of special relativity and electro-dynamics. The expressions for the Lagrange function are defined, and the conservation laws are derived. An analogy is drawn both in the case of the absence of sources and currents in the Maxwell equations and in their presence.

Density Wave Measurements in a Rectangular Clarifier

1983 ◽  
Vol 18 (1) ◽  
pp. 129-150 ◽  
Author(s):  
Mark K. Watson ◽  
R.R. Hudgins ◽  
P.L. Silveston
Keyword(s):  
Power Spectrum ◽  
Internal Wave ◽  
Internal Waves ◽  
Wave Motion ◽  
Wave Amplitude ◽  
Suspended Solids ◽  
Small Volume ◽  
Density Wave ◽  
Measure Concentration ◽  
Wave Measurements

Abstract Internal wave motion was studied in a laboratory rectangular, primary clarifier. A photo-extinction device was used as a turbidimeter to measure concentration fluctuations in a small volume within the clarifier as a function of time. The signal from this device was fed to a HP21MX minicomputer and the power spectrum plotted from data records lasting approximately 30 min. Results show large changes of wave amplitude as frequency increases. Two distinct regions occur: one with high amplitudes at frequencies below 0.03 Hz, the second with very small amplitudes appears for frequencies greater than 0.1 Hz. The former is associated with internal waves, the latter with flow-generated turbulence. Depth, velocity in the clarifier and inlet suspended solids influence wave amplitudes and the spectra. A variation with position or orientation of the probe was not detected. Contradictory results were found for the influence of flow contraction baffles on internal wave amplitude.

Generation of vertical fine structure in inhomogeneous flow by inertial-gravity internal waves

1993 ◽  
Vol 4 (4) ◽  
pp. 307-315
Author(s):  
A. A. Belobrov ◽  
A. A. Slepyshev ◽  
V. S. Shamov
Keyword(s):  
Fine Structure ◽  
Internal Waves ◽  
Inhomogeneous Flow
Sign in / Sign up

Export Citation Format

Share Document