Evolution of Rayleigh-Taylor instability under interface discontinuous acceleration induced by radiation.
Evolution of Rayleigh-Taylor instability under interface discontinuous acceleration induced by radiation.
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DOI：
10.1103/physreve.101.043115
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发表时间：
2020-04
期刊：
影响因子：
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通讯作者：
Zehua Hu;You-sheng Zhang;Bao-lin Tian
中科院分区：
文献类型：
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作者：
Zehua Hu;You-sheng Zhang;Bao-lin Tian
辐射背景下的瑞利-泰勒不稳定性（RTI）在工程应用和自然现象中都很常见。在光学薄和不可压缩的极限下，相应的问题可以简化为界面不连续加速度（IDA）RTI问题，但迄今为止只在线性阶段进行了研究。本文对IDA-RTI的整个演化过程进行了数值和理论研究，特别是对线性阶段之后的阶段进行了研究。结果表明，IDA-RTI问题与经典RTI问题等价，并引入了有效加速度g_{eff}^{*}。进一步证明了IDA-RTI发生的充要条件是g_{eff}^{*}>0（从重流体到轻流体）。这个标准意味着IDA-RTI可以发生在（i）重流体支持（或加速）轻流体或（ii）两种流体具有相同的密度时，与经典的RTI问题相反。此外，准稳态气泡和尖峰速度的理论预测与定量的准确性，显示出良好的协议与数值模拟的结果在很宽的范围内的密度比和加速配置。
Rayleigh-Taylor instability (RTI) under radiation background is commonly found in both engineering applications and natural phenomena. In the optically thin and incompressible limit, the corresponding problem can be simplified as an interface discontinuous acceleration (IDA) RTI problem, but to date has only been studied in the linear stage. In this paper, the entire IDA-RTI evolution was studied numerically and theoretically, particularly for the stages beyond the linear stage. The results show that the IDA-RTI problem is equivalent to the classical RTI with the effective acceleration g_{eff}^{*} that is introduced in this work. Moreover, our studies further show that IDA-RTI can occur if and only if g_{eff}^{*}>0 (from heavy fluid to light fluid). This criterion means that IDA-RTI can occur when (i) heavy fluid supports (or accelerates) the light fluid or (ii) the two fluids have the same density, in contrast to the classical RTI problem. Moreover, the quasisteady bubble and spike velocities are theoretically predicted with quantitative accuracy, showing good agreement with the results of numerical simulations in a wide range of density ratios and acceleration configurations.