Computational study of the interactions of two bubbles along an interface undergoing the Richtmyer-Meshkov instability
ORAL
Abstract
In addition to its prevalence in astrophysics, the shock-driven growth of~interfacial perturbations (the Richtmyer-Meshkov instability, or RMI) has~important practical consequences in applications of fusion research. Our~objective is to numerically investigate the generation of vortex dipoles~that escape the confines of the mixing region, as well as the~reacceleration of bubbles, by focusing on the interaction of two adjacent~bubbles of different sizes subjected to the RMI. Our hypothesis is that~the escape of a vortex dipole can be predicted from the initial conditions~based on the vorticity associated with the bubbles. Simulations are~performed using an in-house, high-order accurate Discontinuous-Galerkin~code. We demonstrate deviations from existing bubble merging models in the~non-linear regime caused by the interaction of adjacent pairs of spikes,~which had not previously been considered. We further develop a criterion~that predicts the regime that will emerge for a given interface.
*This work is funded by the Lawrence Livermore National Laboratory (LLNL) under subcontract B632749 and was performed under the auspices of the U. S. Department of Energy (DOE) by the LLNL under Contract No. DE-AC52-07NA27344 and the U. S. DOE NNSA Center for Excellence under grant number DE-NA0003869. Furthermore, this work is supported by the U.S. DOE under grant DE-NA0003864 and the XSEDE Comet system under grant TG-CTS130005.
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