Parallel shear flow instabilities in strongly coupled Yukawa liquids: A comparison of generalized hydrodynamic model and molecular dynamics results

J., Ashwin; Ganesh, R.
October 2010
Physics of Plasmas;Oct2010, Vol. 17 Issue 10, p103706
Academic Journal
Using a generalized hydrodynamic (GH) model, the growth rate spectra of Kelvin-Helmholtz (KH) instability has been obtained analytically for a step shear profile in strongly coupled Yukawa liquids. The class of shear flows studied is assumed to be incompressible in nature. The growth rate spectra calculated exhibit viscous damping at high mode numbers, destabilization at stronger coupling, and in the limit τm (viscoelastic relaxation time)→0, reduce to the regular Navier-Stokes growth rate spectra. A direct comparison is made with previous molecular dynamics (MD) simulations [Ashwin J. and R. Ganesh, Phys. Rev. Lett. 104, 215003 (2010)] of KH instability. We find that for a given value of Reynolds number R and coupling parameter 1<Γ<100, the GH and MD growth rates are in a qualitative agreement. The inclusion of the effect of shear heating as an effective coupling parameter Γe appears to improve the quantitative comparison as well.


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