scholarly journals Internal wave scattering in continental slope canyons, Part 2: A comparison of ray tracing and numerical simulations

2017 ◽  
Vol 118 ◽  
pp. 16-30 ◽  
Author(s):  
Robert H. Nazarian ◽  
Sonya Legg
Keyword(s):  
Internal Wave ◽  
Numerical Simulations ◽  
Ray Tracing ◽  
Continental Slope ◽  
Wave Scattering

Vibrational energy distribution in plate excited with random white noise

2021 ◽  
Vol 263 (6) ◽  
pp. 965-969
Author(s):  
Tyrode Victor ◽  
Nicolas Totaro ◽  
Laurent Maxit ◽  
Alain Le Bot
Keyword(s):  
Boundary Conditions ◽  
Energy Distribution ◽  
White Noise ◽  
Numerical Simulations ◽  
Ray Tracing ◽  
Energy Analysis ◽  
Vibrational Energy ◽  
Statistical Energy Analysis ◽  
Vibrational Energy Distribution ◽  
Tracing Method

In Statistical Energy Analysis (SEA) and more generally in all statistical theories of sound and vibration, the establishment of diffuse field in subsystems is one of the most important assumption. Diffuse field is a special state of vibration for which the vibrational energy is homogeneously and isotropically distributed. For subsystems excited with a random white noise, the vibration tends to become diffuse when the number of modes is large and the damping sufficiently light. However even under these conditions, the so-called coherent backscattering enhancement (CBE) observed for certain symmetric subsystems may impede diffusivity. In this study, CBE is observed numerically and experimentally for various geometries of subsystem. Also, it is shown that asymmetric boundary conditions leads to reduce or even vanish the CBE. Theoretical and numerical simulations with the ray tracing method are provided to support the discussion.

scholarly journals Numerical simulations of internal wave generation by convection in water

2015 ◽  
Vol 91 (6) ◽  
Author(s):  
Daniel Lecoanet ◽  
Michael Le Bars ◽  
Keaton J. Burns ◽  
Geoffrey M. Vasil ◽  
Benjamin P. Brown ◽  
...  
Keyword(s):  
Internal Wave ◽  
Numerical Simulations ◽  
Wave Generation ◽  
Internal Wave Generation

scholarly journals Helical Coherent Structures in the Wake of Solitary Internal Waves Breaking on the Continental Slope

2020 ◽  
Author(s):  
Alexander Soloviev ◽  
Breanna Vanderplow ◽  
Cayla Dean
Keyword(s):  
Internal Wave ◽  
Continental Slope ◽  
Internal Waves ◽  
Coherent Structures ◽  
Mirror Symmetry ◽  
Sediment Resuspension ◽  
Substantial Effect ◽  
Solitary Internal Wave ◽  
Spatially Distributed ◽  
Solitary Internal Waves

Abstract Mixing caused by the solitary internal waves or solitons in stratified coastal waters is a primary cause of sediment resuspension and transport. Theoretical, experimental, and modeling studies of solitons have focused on nonlinear wave dynamics to explain their main features. However, the 3D cascade of energy from breaking internal wave solitons to turbulence and mixing in the wave induced wake has received less attention. Observations on the California shelf with a spatially distributed fiber optic sensing system revealed coherent structures in the wake of solitary internal waves breaking on the continental slope1,2. Here, we reproduced this phenomenon with a computational fluid dynamics model. The model demonstrated that the coherent structures in the wake of the breaking solitary internal wave are counterrotating helices. The concept of helicity3 as a topological invariant and a measure of the lack of mirror symmetry of the flow can explain the helical nature of these coherent structures4. Both observational and modeling results are consistent with this theoretical conjecture. These coherent structures have a substantial effect on the sediment transport in the bottom boundary layer, formation of nepheloid layers5, and nutrient fluxes.

Focusing of mode-2 internal solitary-like waves: an unexpected extreme internal wave

2021 ◽  
Author(s):  
Nicolas Castro-Folker ◽  
Christopher Subich ◽  
Marek Stastna
Keyword(s):  
Internal Wave ◽  
Numerical Simulations ◽  
Mode 2 ◽  
Resolution Requirements

<p>We report on numerical simulations of stratified adjustment that yield radially propagating mode-2 waves. The initial inward propagating mode-2 wave increases in amplitude, but it does not lead to significant overturning even during the period of self-interaction near the origin. However, post-focusing, the pycnocline thins and secondary waves propagate into an environment that is very different from the undisturbed stratification. These resulting waves break, and create intrusions above and below the thinned pycnocline. While most experimental realizations of extreme internal solitary-like waves use a rectangular geometry, it should be possible to realize this situation experimentally. We discuss the resolution requirements of this situation, as well as irreversible mixing.</p>

scholarly journals Trapped Core Formation within a Shoaling Nonlinear Internal Wave

2012 ◽  
Vol 42 (4) ◽  
pp. 511-525 ◽  
Author(s):  
Ren-Chieh Lien ◽  
Eric A. D’Asaro ◽  
Frank Henyey ◽  
Ming-Huei Chang ◽  
Tswen-Yung Tang ◽  
...  
Keyword(s):  
Steady State ◽  
Internal Wave ◽  
Continental Slope ◽  
Northern South China Sea ◽  
Spring Tide ◽  
Propagation Speed ◽  
Coordinate Frame ◽  
Surrounding Water ◽  
The Core ◽  
O 10

Abstract Large-amplitude (100–200 m) nonlinear internal waves (NLIWs) were observed on the continental slope in the northern South China Sea nearly diurnally during the spring tide. The evolution of one NLIW as it propagated up the continental slope is described. The NLIW arrived at the slope as a nearly steady-state solitary depression wave. As it propagated up the slope, the wave propagation speed C decreased dramatically from 2 to 1.3 m s−1, while the maximum along-wave current speed Umax remained constant at 2 m s−1. As Umax exceeded C, the NLIW reached its breaking limit and formed a subsurface trapped core with closed streamlines in the coordinate frame of the propagating wave. The trapped core consisted of two counter-rotating vortices feeding a jet within the core. It was highly turbulent with 10–50-m density overturnings caused by the vortices acting on the background stratification, with an estimated turbulent kinetic energy dissipation rate of O(10−4) W kg−1 and an eddy diffusivity of O(10−1) m2 s−1. The core mixed continually with the surrounding water and created a wake of mixed water, observed as an isopycnal salinity anomaly. As the trapped core formed, the NLIW became unsteady and dissipative and broke into a large primary wave and a smaller wave. Although shoaling alone can lead to wave fission, the authors hypothesize that the wave breaking and the trapped core evolution may further trigger the fission process. These processes of wave fission and dissipation continued so that the NLIW evolved from a single deep-water solitary wave as it approached the continental slope into a train of smaller waves on the Dongsha Plateau. Observed properties, including wave width, amplitude, and propagation speed, are reasonably predicted by a fully nonlinear steady-state internal wave model, with better agreement in the deeper water. The agreement of observed and modeled propagation speed is improved when a reasonable vertical profile of background current is included in the model.

Sign in / Sign up

Export Citation Format

Share Document