Abstract-
We present results obtained from large-eddy simulations (LES) of Richtmyer-Meshkov (RM) instability in a rectangular three-dimensional channel with reshock following shock reflection off an end wall. The shock strength, tube geometry and initial interface disturbance were tailored to match the experimental conditions of Vetter and Sturtevant [1], with shock Mach number M = 1.5 and density ratio r = 5 respectively. The LES runs were performed using the stretched-vortex subgrid-scale (SGS) model [2]. The basic numerical method is an advanced version of our hybrid WENO (weighted essentially non oscillatory) scheme [3]. Here WENO is used in thin regions containing shock waves, matched to a conservative tuned centered-difference (TCD) stencil in regions of smooth flow where the SGS model is activated.
The discussion will focus on the development and suitability of the scheme in conjuction with the subgrid model. Presented are the predicted growth and turbulent statistics of the mixing layer produced at the density interface following the two shock passage events. To underscore effectiveness of our approach, comparisons (of spectra and subgrid activity) with alternate method will be shown.
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| Density interface (a) After first shock passage, (b) after reshock shock, (c) isolated interface. Simulation performed with AMROC. |
References
[1] Vetter M. & Sturtevant B. 1995 Experiments on the Richtmyer-Meshkov instability of an air/SF6 interface. Shock waves. 5, 247–2524, 1995.
[2] Misra A. & Pullin D.I. A vortex-based subgrid stress model for large-eddy simulation. Phys Fluids 9, 2443–2454, 1997.
[3] Hill D.J. & Pullin D.I. 2004 Hybrid Tuned Center Difference - WENO Method for Large Eddy Simulations in the Presence of Strong Shocks. J. Comp Phys. In press, 2004.
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