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Title: Spike deceleration and bubble acceleration in the ablative Rayleigh-Taylor instability

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.3497006· OSTI ID:21532097
;  [1];  [2]
  1. Department of Physics, Zhejiang University, Hangzhou 310027 (China)
  2. CAPT, Peking University, Beijing 100871 (China) and LCP, Institute of Applied Physics Computational Mathematics, Beijing 100088 (China)

The nonlinear evolutions of the Rayleigh-Taylor instability (RTI) with preheat is investigated by numerical simulation (NS). A new phase of the spike deceleration evolution in the nonlinear ablative RTI (ARTI) is discovered. It is found that nonlinear evolution of the RTI can be divided into the weakly nonlinear regime (WNR) and the highly nonlinear regime (HNR) according to the difference of acceleration velocities for the spike and the bubble. With respect to the classical RTI (i.e., without heat conduction), the bubble first accelerates in the WNR and then decelerates in the HNR while the spike holds acceleration in the whole nonlinear regime (NR). With regard to the ARTI, on the contrary, the spike first accelerates in the WNR and then decelerates in the HNR while the bubble keeps acceleration in the whole NR. The NS results indicate that it is the nonlinear overpressure effect at the spike tip and the vorticity accumulation inside the bubble that lead to, respectively, the spike deceleration and bubble acceleration, in the nonlinear ARTI. In addition, it is found that in the ARTI the spike saturation velocity increases with the perturbation wavelength.

OSTI ID:
21532097
Journal Information:
Physics of Plasmas, Vol. 17, Issue 12; Other Information: DOI: 10.1063/1.3497006; (c) 2010 American Institute of Physics; ISSN 1070-664X
Country of Publication:
United States
Language:
English