Asymptotic behavior of the mixed mass in Rayleigh–Taylor and Richtmyer–Meshkov instability induced flows
Asymptotic behavior of the mixed mass in Rayleigh–Taylor and Richtmyer–Meshkov instability induced flows
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DOI：
10.1063/1.4951018
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发表时间：
2016-05
影响因子：
2.2
通讯作者：
Ye Zhou;W. Cabot;B. Thornber
中科院分区：
文献类型：
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作者：
Ye Zhou;W. Cabot;B. Thornber
Rayleigh-Taylor不稳定性（RTI）和Richtmyer-Meshkov不稳定性（RMI）是惯性约束聚变研究中的重要问题，也与许多天体物理流体动力学问题有关。到目前为止，大部分的注意力都集中在混合宽度的后期缩放上，它被用作流体混合程度的替代。然而，混合质量的实际量可以被看作是由于流体动力学不稳定性的混合层的演变的更直接的指标。尽管它的重要性，有没有系统的研究，迄今为止，无论是RTI或RMI诱导流的混合质量的缩放。本文提出了用归一化混合质量来衡量混合质量效率的方法。六个大型数值模拟数据库已被采用：RTI的情况下，重轻流体密度比为1.5，3，和9;单冲击RMI的情况下，密度比为3和20;和一个再冲击RMI的情况下，密度比为3。使用模拟流场，归一化的混合质量导数被证明是更敏感的区别与阿特伍德数的RTI流的变化。此外，与传统的混合度参数θ和Θ相比，对于RTI和RMI流，θ被证明可以提供更一致的结果。
Rayleigh–Taylor instability (RTI) and Richtmyer–Meshkov instability (RMI) are serious practical issues in inertial confinement fusion research, and also have relevance to many cases of astrophysical fluid dynamics. So far, much of the attention has been paid to the late-time scaling of the mixed width, which is used as a surrogate to how well the fluids have been mixed. Yet, the actual amount of mixed mass could be viewed as a more direct indicator on the evolution of the mixing layers due to hydrodynamic instabilities. Despite its importance, there is no systematic study as yet on the scaling of the mixed mass for either the RTI or the RMI induced flow. In this article, the normalized mixed mass (Ψ) is introduced for measuring the efficiency of the mixed mass. Six large numerical simulation databases have been employed: the RTI cases with heavy-to-light fluid density ratios of 1.5, 3, and 9; the single shock RMI cases with density ratios of 3 and 20; and a reshock RMI case with density ratio of 3. Using simulated flow fields, the normalized mixed mass Ψ is shown to be more sensitive in discriminating the variation with Atwood number for the RTI flows. Moreover, Ψ is demonstrated to provide more consistent results for both the RTI and RMI flows when compared with the traditional mixedness parameters, Ξ and Θ.