Nonlinear Evolution of two Gravitational Instabilities and Thermal Conduction Loss at Fractal Interface

分形界面处两种引力不稳定性和热传导损失的非线性演化

基本信息

批准号：
11680486
负责人：
NISHIHARA Katsunobu
金额：
$ 2.37万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

项目摘要

1. We have developed a weakly nonlinear theory of ablative Rayleigh-Taylor (RT) instability with a finite bandwidth Included self-consistently. The theory includes up to third order nonlinearity that results in saturation of linear growth and determines weakly nonlinear growth. It is found that the ablation effects reduce both the saturation amplitude of the linear growth and the weakly nonlinear growth. They are evaluated for plastic and DT targets. The weakly nonlinear growth is shown given by the product pf the linear growth and the saturation amplitude.2. A third order nonlinear theory of Richtmyer-Meshkov (RM) instability has been developed by treating unstable interface as a vortex sheet with density jump. Nonlinear growth rates of spike and bubble are shown to agree well with hydrodynamic simulations. Circulation varies locally with time due to the density jump at the sheet and it introduces stretching and shrinking of the interface locally.3. We have developed a molecular dynamic simulation program to treat RM instability in a cylindrical geometry, that conventional hydrodynamic codes fails to simulate. With the use of the code, we have investigated the stability of converging shocks and the nonlinear growth of RM instability, We have shown the increase of the nonlinear growth due to multiple shocks rebounded at the center and its dependence on mode number.4. We have developed self-similar solutions of laser implosion in which thermal conduction plays an important rote by using Lie group theory. This model has been applied for hydrodynamically equivalent implosions in order to design future experimental facility for ignition and high gain in inertial fusion energy research.

1。我们已经开发了一种弱的非线性理论，即具有有限的带宽，包括自一度的带宽。该理论包括高达三阶非线性，从而导致线性生长饱和并确定弱非线性生长。发现消融效应减少了线性生长的饱和幅度和弱非线性生长。对它们进行塑料和DT靶标的评估。弱非线性生长由乘积PF表示线性生长和饱和幅度给出。2。通过将不稳定的界面视为具有密度跳跃的涡流表，已经开发出了Richtmyer-Meshkov（RM）不稳定性的三阶非线性理论。尖峰和气泡的非线性生长速率已显示与流体动力学模拟非常吻合。循环随时间而变化，因为纸板的密度跳跃，它引入了界面的拉伸和收缩。3。我们已经开发了一个分子动力学模拟程序，以治疗圆柱几何形状中的RM不稳定性，该程序传统的流体动力代码无法模拟。随着代码的使用，我们研究了融合冲击的稳定性和RM不稳定性的非线性增长，我们显示了由于中心及其对模式数字的依赖性反弹而导致非线性增长的增加。4。我们已经开发了激光内爆的自相似溶液，其中热传导通过使用谎言组理论起着重要的死记硬背。该模型已用于流体动力学上的内爆，以设计未来的实验设施，以进行惯性融合能量研究的点火和高增益。