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应用直接数值模拟研究标量湍流耗散的空间结构.在均匀标量湍流场和槽道湍流的非均匀标量湍流场中都发现了标量湍流耗散呈片状结构.通过标量湍流耗散的输运方程的分析,研究了脉动变形率张量在标量耗散生成中的作用,发现脉动标量梯度在脉动变形率张量的第3主轴方向占优,从而解释标量湍流耗散片状结构的产生原因.
The direct numerical simulation is used to study the spatial structure of the scalar turbulence dissipation. The scalar turbulence is dissipated in the form of sheet-like structures in the non-uniform scalar turbulent flow field with uniform scalar turbulence and channel turbulence. The transport equation The effect of pulsation deformation rate tensors on the generation of scalar dissipation is studied. It is found that the pulsating scalar gradient predominates on the 3rd principal axis of the pulsation strain rate tensor, which explains the cause of the dissipative sheet-like structure of the scalar turbulence.