Numerical investigation of nonlinear ablative single-mode Rayleigh–Taylor instability in the presence of preheating
Numerical investigation of nonlinear ablative single-mode Rayleigh–Taylor instability in the presence of preheating
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DOI：
10.1088/0031-8949/2013/t155/014018
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发表时间：
2013-07
期刊：
影响因子：
2.9
通讯作者：
L. F. Wang;W. Ye;W. Y. Zhang;X. He
中科院分区：
文献类型：
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作者：
L. F. Wang;W. Ye;W. Y. Zhang;X. He
弱预热和强预热的非线性烧蚀单模瑞利-泰勒不稳定性 (RTI) 已进行数值研究。获得的线性增长率的数值结果与自洽线性稳定性分析大体一致（Goncharov 等人 1996 Phys. Plasmas 3 4665）。预热对烧蚀 RTI (ARTI) 的影响显示出降低其线性增长率并减轻弱非线性增长。研究发现，ARTI 的非线性演化强烈依赖于预热强度和扰动波长。 ARTI 的非线性演化存在三种典型的波长扰动。在预热较弱的 ARTI 中，对于短波长扰动，尖峰可能会在高度非线性状态下破裂，而对于中/长波长扰动，尖峰头部会出现开尔文-亥姆霍兹蘑菇形图案。在对中波长扰动进行强烈预热的 ARTI 中，可以形成喷射状尖峰，尽管尖峰在其经典 RTI（无导热性）对应物中仍然会破裂。总之，我们的数值研究表明预热会对 ARTI 的非线性演化产生显着影响。因此，它应该包含在预热起着至关重要作用的应用中，例如惯性约束聚变内爆和超新星爆炸。
Nonlinear ablative single-mode Rayleigh–Taylor instability (RTI) with weak and strong preheatings has been investigated numerically. The numerical results for the linear growth rates obtained are in general agreement with a self-consistent linear stability analysis (Goncharov et al 1996 Phys. Plasmas 3 4665). The effects of preheating on the ablative RTI (ARTI) are shown to reduce its linear growth rate and mitigate the weakly nonlinear growth. It was found that the nonlinear evolution of the ARTI is strongly dependent on the preheating intensity and perturbation wavelength. There are three typical wavelength perturbations for the nonlinear evolution of the ARTI. In the ARTI with weak preheating, for a short-wavelength perturbation the spike can be ruptured in the highly nonlinear regime and for a middle/long-wavelength perturbation the Kelvin–Helmholtz mushroom-shaped patterns appear at the spike heads. In the ARTI with strong preheating for a middle-wavelength perturbation, jet-like spikes can be formed though the spikes can still be ruptured in its classical RTI (without thermal conductivity) counterpart. In summary, our numerical studies indicate that the preheating can have a pronounced influence on the nonlinear evolutions of the ARTI. Thus, it should be included in applications where preheating plays a vital role, such as inertial confinement fusion implosions and supernova explosions.