Mapping closure and non-Gaussianity of the scalar probability density functions in isotropic turbulence
Mapping closure and non-Gaussianity of the scalar probability density functions in isotropic turbulence
复制标题
各向同性湍流中标量概率密度函数的映射封闭性和非高斯性
DOI：
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发表时间：
1991
期刊：
影响因子：
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通讯作者：
F. Gao
中科院分区：
文献类型：
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作者：
F. Gao
本文试图对湍流标量场的振幅映射封闭性进行评估。封闭的假设被证明是在非常好的协议从各向同性湍流的被动标量的直接数值模拟（DNS）的结果。振幅映射闭包被用来研究各向同性流中单点标量概率密度函数（pdf）的非高斯性质。它表明，一般的标量PDF放松到高斯分布时，标量方差是非常小的，只能预期。一些由初始和边界条件施加的非高斯特性在标量演化过程中一直存在。
An attempt is made to assess the amplitude mapping closure for turbulent scalar fields. The closure assumption is shown to be in very good agreement with the results obtained from direct numerical simulations (DNS) of passive scalars in isotropic turbulence. The amplitude mapping closure is then employed to investigate the non‐Gaussian properties of one‐point scalar probability density functions (pdf) in isotropic flows. It is shown that the general relaxation of a scalar pdf to a Gaussian distribution can only be expected when the scalar variance is very small. Some non‐Gaussian characteristics imposed by initial and boundary conditions persist throughout the course of scalar evolution.