Wake structures of a particle in straight and curved flows
Wake structures of a particle in straight and curved flows
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直线流和曲线流中粒子的尾流结构
DOI：
10.1007/978-3-319-30602-5_24
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Shintaro Takeuchi and Takeo Kajishima
中科院分区：
文献类型：
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作者：
Toshiaki Fukada;Shintaro Takeuchi and Takeo Kajishima
为了研究非轴对称剪切对颗粒尾迹结构的影响，模拟了单个球形颗粒在平行（流向）剪切流和弯曲（横向）剪切流中的绕流。颗粒雷诺数和剪切雷诺数的范围是通过假设颗粒尺寸与湍流中的Kolmogorov长度尺度相当来确定的。平行剪切对扰动速度的影响很小。对于弯曲剪切，尾流区域在空间中偏转。然而，尾流的宽度在颗粒附近几乎不变。对于固粒和平动颗粒情况，即使相对于平动颗粒的未扰动流的流线彼此相似，环境压力梯度的不同也会导致速度分布的不同。
To investigate the effect of non-axisymmetric shear on the wake structure of a particle, the flows around a single spherical particle in the following two kinds of shear flows are simulated: parallel (streamwise) shear and curved (cross-streamwise) shear flows. The ranges of the particle Reynolds number and the shear Reynolds number are determined by assuming that the particle size is comparable to the Kolmogorov length scale in a turbulent flow. The effect of the parallel shear on the perturbation velocity is small. For the curved shear, the wake region is deflected in space. However, the width of the wake is almost unchanged near the particle. For the fixed and translating particle cases, even if the streamlines of the undisturbed flow relative to the particle translation are similar to each other, the difference of the ambient pressure gradient makes the difference of the velocity distributions.