Non-linear characteristics of Rayleigh-Taylor instable perturbations

作者：Fan Zhengfeng^*; Luo Jisheng

来源：Acta Mechanica Sinica, 2008, 24(2): 143-149.

DOI：10.1007/s10409-007-0135-9

• inertial confinement fusion
• Rayleigh-Taylor instability
• non-linear characteristics
• direct numerical simulation

The direct numerical simulation method is adopted to study the non-linear characteristics of Rayleigh-Taylor instable perturbations at the ablation front of a 200 mu m planar CH ablation target. In the simulation, the classical electrical thermal conductivity is included, and NND difference scheme is used. The linear growth rates obtained from the simulation agree with the Takabe formula. The amplitude distribution of the density perturbation at the ablation front is obtained for the linear growth case. The non-linear characteristics of Rayleigh-Taylor instable perturbations are analyzed and the numerical results show that the amplitude distributions of the compulsive harmonics are very different from that of the fundamental perturbation. The characteristics of the amplitude distributions of the harmonics and their fast growth explain why spikes occur at the ablation front. The numerical results also show that non-linear effects have relations with the phase differences of double mode initial perturbations, and different phase differences lead to varied spikes.

• 出版日期2008-4
• 单位天津大学