Boundary-layer-separation-driven vortex shedding beneath internal solitary waves of depression

  title={Boundary-layer-separation-driven vortex shedding beneath internal solitary waves of depression},
  author={Payam Aghsaee and Leon Boegman and Peter J. Diamessis and Kevin G. Lamb},
  journal={Journal of Fluid Mechanics},
  pages={321 - 344}
Abstract We investigate global instability and vortex shedding in the separated laminar boundary layer beneath internal solitary waves (ISWs) of depression in a two-layer stratified fluid by performing high-resolution two-dimensional direct numerical simulations. The simulations were conducted with waves propagating over a flat bottom and shoaling over relatively mild $(S= 0. 05)$ and steep $(S= 0. 1)$ slopes. Over a flat bottom, the potential for vortex shedding is shown to be directly… 

Instability and cross-boundary-layer transport by shoaling internal waves over realistic slopes

Internal solitary and solitary-like waves (ISW) play an important role in mixing and sediment resuspension in naturally occurring stratified fluids, primarily through various instabilities and

Internal wave boundary layer interaction: A novel instability over broad topography

It has been known for some time that internal wave-induced currents can drive near bed instabilities in the bottom boundary layer over a flat bottom. When the bottom is not flat, the situation can

Vortex generation due to internal solitary wave propagation past a sidewall constriction

Abstract Internal solitary waves in the coastal ocean propagate in a complex environment, with variations in the background currents and stratification and with topography along both the bottom (e.g.

Topographically generated internal waves and boundary layer instabilities

Flow over topography has been shown to generate finite amplitude internal waves upstream, over the topography and downstream. Such waves can interact with the viscous bottom boundary layer to produce

Numerical investigation of internal solitary wave induced global instabilities

We have in this study investigated the global instability developing beneath large internal solitary waves (ISW) of depression in a wave tank. To perform this study, the numerical tool Basilisk has

Shoaling mode-2 internal solitary-like waves

The propagation of a train of mode-2 internal solitary-like waves (ISWs) over a uniformly sloping, solid topographic boundary, has been studied by means of a combined laboratory and numerical

Near-Bottom Turbulence and Sediment Resuspension Induced by Nonlinear Internal Waves

Abstract : The transition to fully turbulence under fully nonlinear internal solitary waves (NLIWs) has been investigated. Very well resolved Large Eddy Simulations (LES) of the separated bottom

Internal Wave Breaking and Dissipation Mechanisms on the Continental Slope/Shelf

  • K. Lamb
  • Geology, Environmental Science
  • 2014
Internal waves are important physical phenomena on the continental shelf/slope. They are often very energetic, and their breaking provides an important dissipation and mixing mechanism, with

Self-sustained instability, transition, and turbulence induced by a long separation bubble in the footprint of an internal solitary wave. I. Flow topology

Using a high-accuracy-and-resolution implicit Large Eddy Simulation we study the development of the bottom boundary layer (BBL) driven by the long separation bubble which forms under an internal

Bed failure induced by internal solitary waves

The pressure field inside a porous bed induced by the passage of an Internal Solitary Wave (ISW) of depression is examined using high-accuracy numerical simulations. Assuming a two-layer,

Breaking of shoaling internal solitary waves

The breaking of fully nonlinear internal solitary waves of depression shoaling upon a uniformly sloping boundary in a smoothed two-layer density field was investigated using high-resolution

Experimental evidence of internal solitary wave-induced global instability in shallow water benthic boundary layers

Experimental evidence is presented in support of the theoretical prediction of Diamessis and Redekopp [J. Phys. Oceanogr. 36, 784 (2006)] for wave-induced vortex shedding at the lower solid boundary

Bottom Boundary Layer Instabilities Induced By Nonlinear Internal Waves

Internal solitary waves (commonly referred to as ”nonlinear internal waves” due to the balance between nonlinearity and dispersion, with the intense nonlinearity represented by very strong

Structure and Generation of Turbulence at Interfaces Strained by Internal Solitary Waves Propagating Shoreward over the Continental Shelf

Abstract Detailed observations of the structure within internal solitary waves propagating shoreward over Oregon's continental shelf reveal the evolving nature of interfaces as they become unstable

Numerical investigation of solitary internal wave-induced global instability in shallow water benthic boundary layers

Abstract The time-dependent boundary layer induced by a weakly nonlinear solitary internal wave in shallow water is examined through direct numerical simulation. Waves of depression and elevation are

The motion of an internal solitary wave of depression over a fixed bottom boundary in a shallow, two-layer fluid

The motion of a large-amplitude internal solitary wave of depression over a fixed bottom boundary in a shallow, two-layer fluid is investigated experimentally. Measurements of the velocity fields

Flow separation and resuspension beneath shoaling nonlinear internal waves

[1] Laboratory observations are presented showing the structure and dynamics of the turbulent bottom boundary layer beneath nonlinear internal waves (NLIWs) of depression shoaling upon sloping

Vortex shedding and sediment resuspension associated with the interaction of an internal solitary wave and the bottom boundary layer

In this note we present results on the interaction of fully nonlinear internal solitary waves with the oceanic bottom boundary layer. We show that for fully nonlinear solitary waves it is the

A numerical investigation of solitary internal waves with trapped cores formed via shoaling

  • K. Lamb
  • Physics, Environmental Science
    Journal of Fluid Mechanics
  • 2002
The formation of solitary internal waves with trapped cores via shoaling is investigated numerically. For density fields for which the buoyancy frequency increases monotonically towards the surface,

Internal solitary waves of elevation advancing on a shoaling shelf

A sequence of three internal solitary waves of elevation were observed propagating shoreward along a near‐bottom density interface over Oregon's continental shelf. These waves are highly turbulent