Intermittency in passive scalar turbulence under the uniform mean scalar gradient
Intermittency in passive scalar turbulence under the uniform mean scalar gradient
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DOI：
10.1063/1.2206810
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发表时间：
2006-05-01
影响因子：
4.6
通讯作者：
Gotoh, Toshiyuki
中科院分区：
文献类型：
--
作者：
Watanabe, Takeshi;Gotoh, Toshiyuki
采用高分辨率直接数值模拟方法，研究了均匀平均标量梯度下湍流对被动标量的小尺度统计特性。结果表明，在所研究的雷诺数范围内，与平均梯度平行和垂直方向的标量增量结构函数的标度指数是相同的，且在大范围内饱和约1.3，且它们与大尺度标量注入方案有关。在惯性对流范围内，标量增量的概率密度函数的尾部用由一点标量概率密度函数的饱和和尾部推导出的标量形式很好地拟合得很好。(C)2006年美国物理研究所。
Small scale statistics of a passive scalar convected by turbulence under the uniform mean scalar gradient is studied by high-resolution direct numerical simulation. It is found that the scaling exponents of the structure functions of scalar increments in parallel and perpendicular directions to the mean gradient are the same and saturate approximately 1.3 at large order, and that they are dependent on scalar injection scheme at large scales within the Reynolds numbers studied. Tails of the probability density functions for the scalar increment in the inertial convective range are well fitted by a scaling form inferred from the saturation and the tail of the one point scalar probability density function. (C) 2006 American Institute of Physics.