Nonlinear mixing behavior of the three-dimensional Rayleigh-Taylor instability at a decelerating interface.
We report results from the first experiments to explore the evolution of the Rayleigh-Taylor (RT) instability from intentionally three-dimensional (3D) initial conditions at an embedded, decelerating interface in a high-Reynolds-number flow. The experiments used {approx}5 kJ of laser energy to produce a blast wave in polyimide and/or brominated plastic having an initial pressure of {approx}50 Mbars. This blast wave shocked and then decelerated the perturbed interface between first material and a lower-density, C foam. This caused the formation of a decelerating interface with an Atwood number {approx}2/3, producing a long-term positive growth rate for the RT instability. The initial perturbations were a 3D perturbation in an ''egg-crate'' pattern with feature spacings of 71 {micro}m in two orthogonal directions and peak-to-valley amplitudes of 5 {micro}m. The resulting RT spikes were observed to overtake the shock waves at the undisturbed, ''free-fall'' rate, and to subsequently deliver material from behind the interface to the forward shock. This result is unanticipated by prior simulations and models.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 892784
- Report Number(s):
- UCRL-JRNL-203479; TRN: US200623%%576
- Journal Information:
- Physics of Plasmas, vol. 11, no. 5, May 1, 2004, pp. 2829, Journal Name: Physics of Plasmas, vol. 11, no. 5, May 1, 2004, pp. 2829
- Country of Publication:
- United States
- Language:
- English
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