Finite shock model of density in supersonic turbulence
Finite shock model of density in supersonic turbulence
复制标题
超音速湍流密度有限激波模型
DOI：
10.1093/mnrasl/slac123
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发表时间：
2022
影响因子：
--
通讯作者：
Collins, David C.
中科院分区：
文献类型：
--
作者：
Rabatin, Branislav;Collins, David C.
在等温、超音速、湍流气体中密度的概率分布近似为对数正态分布。这种行为可以追溯到在介质中传播的激波，它通过局部音速马赫数平方的随机因子随机调整密度。假设某一气体包经历大量的冲击，根据中心极限定理，得到的密度分布是对数正态分布。我们探索了一个模型，其中气体包裹在松弛到环境密度之前经历有限次冲击，导致密度分布偏离对数正态分布。我们对该模型进行了数值模拟，其有效值马赫数从低至0.1的亚音速到25的超音速不等。我们发现对有限公式的拟合比对数正态曲线好一个数量级。该模型甚至自然地扩展到亚音速流动，那里没有激波存在。
The probability distribution of density in isothermal, supersonic, turbulent gas is approximately lognormal. This behaviour can be traced back to the shock waves travelling through the medium, which randomly adjust the density by a random factor of the local sonic Mach number squared. Provided a certain parcel of gas experiences a large number of shocks, due to the central limit theorem, the resulting distribution for density is lognormal. We explore a model in which parcels of gas undergo finite number of shocks before relaxing to the ambient density, causing the distribution for density to deviate from a lognormal. We confront this model with numerical simulations with various rms Mach numbers ranging from subsonic as low as 0.1 to supersonic at 25. We find that the fits to the finite formula are an order of magnitude better than a lognormal. The model naturally extends even to subsonic flows, where no shocks exist.
DOI：
10.3847/1538-3881/ab63d5/data
发表时间：
2020-02
期刊：
--
影响因子：
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作者：
Y. Zou;Fuxiang Liu;Bin Liao;Yu Liu;Yating Chai;Lei Xia
通讯作者：
Y. Zou;Fuxiang Liu;Bin Liao;Yu Liu;Yating Chai;Lei Xia