Abstract Details
Blast-wave-driven Rayleigh-Taylor Instabilities
Author: Bruce A. Fryxell
Requested Type: Oral Only
Submitted: 2009-03-31 16:22:46
Co-authors: A. Budde, C.C. Kuranz, R.P. Drake, M. Grosskopf, C. Krauland, D. Marion, B.A. Remington, H.F. Robey, J.F. Hansen, A.R. Miles, J. Knauer, D. Arnett, C. Meakin, T. Plewa, N. Hearn
Contact Info:
University of Michigan
2455 Hayward Street
Ann Arbor, MI 48109
USA
Abstract Text:
The interaction of a blast wave generated in a supernova explosion with a composition discontinuity in the star’s envelope produces crossed density and pressure gradients, which are unstable to the growth of Rayleigh-Taylor modes. This instability is responsible for considerable mixing of nuclear species in the ejecta and produces observable effects in the light curve and spectrum of the explosion. Blast-wave-driven instabilities of this type have been studied numerically as well as experimentally using the Omega Laser at the University of Rochester. Initial comparisons between the numerical simulations and the experiments show poor agreement. The simulations show the classic bubble and spike morphology of the Rayleigh-Taylor instability, with well-developed mushroom caps at the tips of the spikes. However, the mushroom caps appear much smaller in the experimental results than in the simulations for two-dimensional initial perturbations and seem to be completely absent for three-dimensional initial perturbations. Also, some experiments show mass extending beyond the spikes and penetrating almost to the shock front. This effect is completely absent from the numerical simulations. This talk will discuss possible causes of these discrepancies.
This research was supported by the DOE NNSA under the Predictive Science Academic Alliance Program by grant DEFC52-08NA28616.
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