Two-point correlation equations for variable density turbulence
Two-point correlation equations for variable density turbulence
复制标题
变密度湍流的两点相关方程
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
P. Spitz
中科院分区：
文献类型：
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作者：
T. Clark;P. Spitz
本文导出了一套完整的变密度湍流的两点关联方程，使其在质量加权变量（Favre平均）中保持一致。推导是基于雷诺应力张量的两点概括。将方程关于两点之间的间隔变换到傅立叶空间。相关方程以及傅立叶变换方程提供了在单点方程中不可用的见解。由于非螺线管场的各向同性标量-矢量相关函数的复杂性，谱闭包的推导比常密度闭包或单点变密度闭包复杂得多。提出了相关函数的几个必要的约束条件。此外，一个简单的光谱模型，满足这些约束条件的说明性的目的，并讨论了两点的相关性和它们的关系，在一点的衍生所产生的相应的相关性。
A complete set of two-point correlation equations for variable-density turbulence is derived to consistent order in mass-weighted variables (Favre averaging). The derivation is based on a two-point generalization of the Reynolds stress tensor. The equations are transformed with respect to the separation between the two points to Fourier space. The correlation equations, as well as the Fourier-transformed equations, provide insights that are unavailable in the one-point equations. The derivation of spectral closures is significantly more complicated than that of constant-density closures or one-point variable-density closures due to the complex nature of isotropic scalar-vector correlation functions for nonsolenoidal fields. Several necessary constraints for the correlation functions are presented. In addition, a simple spectral model that satisfies these constraints is presented for illustrative purposes, and a discussion of the two-point correlations and their relationship to the corresponding correlations arising in one-point derivations is provided.