Destabilizing effect of density gradient on the Kelvin–Helmholtz instability

Wang, L. F.; Xue, C.; Ye, W. H.; Li, Y. J.
November 2009
Physics of Plasmas;Nov2009, Vol. 16 Issue 11, p112104
Academic Journal
In this paper, we derive explicit analytic formulas for the linear growth rate and frequency of the Kelvin–Helmholtz instability in fluids with the density gradient. The analytic formulas are in excellent agreement with the results of two-dimensional numerical simulation. We found that the density gradient effect enforces (destabilizes) the Kelvin–Helmholtz instability by increasing its linear growth rate in the direction normal to the perturbed interface. The frequency is reduced (stabilized) by the density gradient effect, i.e., the density gradient decreases the transmission of the perturbation in the direction along to the perturbed interface. In most cases, the combined effect of density and velocity gradients stabilizes the Kelvin–Helmholtz instability.


Related Articles

  • The evolution of a localized nonlinear wave of the Kelvin-Helmholtz instability with gravity. Orazzo, Annagrazia; Hoepffner, Jérôme // Physics of Fluids;Nov2012, Vol. 24 Issue 11, p112106 

    At the interface between two fluids of different density and in the presence of gravity, there are well known periodic surface waves which can propagate for long distances with little attenuation, as it is for instance the case at the surface of the sea. If wind is present, these waves...

  • Richtmyer-Meshkov instability of an interface between two media due to passage of two successive shocks. Charakhch'an, A. // Journal of Applied Mechanics & Technical Physics;Jan2000, Vol. 41 Issue 1, p23 

    The instability of a free surface of aluminum after passage of two shocks that follow one after the other at a certain time interval is studied numerically. The first shock is rather strong (the postshock pressure is about 75 GPa). It is shown that if at the moment when the second shock arrives...

  • Analysis of second-harmonic generation of Lamb waves using a combined method in a two-layered solid waveguide. Xiang, Yanxun; Deng, Mingxi; Xuan, Fu-Zhen // Journal of Applied Physics;Jul2009, Vol. 106 Issue 2, p024902 

    Within the second-order perturbation treatment, the present work analyzed the complex second-harmonic generation of Lamb waves in a two-layered solid waveguide by combining the modal analysis method and the nonlinear reflection of acoustic waves at interfaces. The formal solution of the...

  • Computer simulation study of the local pressure in a spherical liquid-vapor interface. El Bardouni, H.; Mareschal, M.; Lovett, R.; Baus, M. // Journal of Chemical Physics;12/1/2000, Vol. 113 Issue 21 

    The pressure profiles across a liquid-vapor interface introduced previously [J. Chem. Phys. 106, 635 (1997)] have been evaluated with the aid of molecular dynamics simulations for a system of particles interacting via a (truncated and shifted) Lennard-Jones potential. This investigation extends...

  • Rayleigh—Taylor stability for a normal shock wave—density discontinuity interaction. Fraley, Gary // Physics of Fluids (00319171);Feb86, Vol. 29 Issue 2, p376 

    The solution for the perturbation growth of a shock wave striking a density discontinuity at a material interface is developed. The Laplace transformation of the perturbation results in an equation which has a simple solution for weak shock waves. The solution for strong shock waves may be given...

  • Compressible inviscid instability of rapidly expanding spherical material interfaces. Mankbadi, Mina R.; Balachandar, S. // Physics of Fluids;Mar2012, Vol. 24 Issue 3, p034106 

    A high-order weighted essentially non-oscillatory scheme is employed to investigate the stability of a rapidly expanding material interface produced by a spherical shock tube. The flow structure is characterized by a forward moving primary shock, a backward moving secondary shock, and a...

  • Simulation of x-ray diffraction intensity variation of W/Si multilayer after annealing. He, Xian-chang; Shen, He-sheng; Wu, Zi-qin // Journal of Applied Physics;4/1/1990, Vol. 67 Issue 7, p3481 

    Presents a study which performed a computer simulation of small angle x-ray diffraction intensities of the W/Si multilayer with possible structural models of interfaces after annealing, with or without systematic and random deviations. Examples of models which are related to different interface...

  • Structure of the liquid–vapor interface of water. Townsend, R. Michael; Gryko, Jan; Rice, Stuart A. // Journal of Chemical Physics;5/1/1985, Vol. 82 Issue 9, p4391 

    Presents the results of computer simulations of the liquid-vapor interface of water. Liquid-vapor interface of a free cluster; Monte Carlo minimizations and Lennard-Jones interaction between oxygen atoms; Density profile through the liquid-vapor interface.

  • Computer simulation of fluids interacting with fluctuating walls. Lupkowski, Mark; van Swol, Frank // Journal of Chemical Physics;7/1/1990, Vol. 93 Issue 1, p737 

    We present a new method for performing molecular simulations of systems with planar interfaces in the presence of fluctuating walls. The technique is essentially the realization of a frictionless piston exerting an external potential on a fluid within a container. The simulation cell is...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics