Direct numerical simulation of flow past a transversely rotating sphere up to a Reynolds number of 300 in compressible flow
Direct numerical simulation of flow past a transversely rotating sphere up to a Reynolds number of 300 in compressible flow
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可压缩流中雷诺数高达 300 的横向旋转球体流动的直接数值模拟
DOI：
10.1017/jfm.2018.756
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发表时间：
2018
影响因子：
3.7
通讯作者：
K.
中科院分区：
文献类型：
--
作者：
Nagata;T.;Nonomura;T.;Takahashi;S.;Mizuno;Y.;and Fukuda;K.
本文采用直接数值模拟方法研究了高马赫数、低雷诺数下旋转球绕流的气动力系数和尾迹结构随转速和马赫数的变化规律。通过求解三维可压缩Navier-Stokes方程进行模拟。自由流雷诺数（基于自由流速度、密度和粘性系数以及球体直径）被设定为在100和300之间，自由流马赫数被设定为在0.2和2.0之间，并且由赤道上方的自由流速度和表面速度的比率限定的无量纲旋转速率被设定为在0.0和1.0之间。（2）在亚音速条件下，阻力系数随转速的增大而增大，而在超音速条件下，阻力系数随马赫数的增大而减小;（3）随着马赫数的增加，尾流结构的模态变得类似低雷诺数。
In this study, direct numerical simulation of the flow around a rotating sphere at high Mach and low Reynolds numbers is conducted to investigate the effects of rotation rate and Mach number upon aerodynamic force coefficients and wake structures. The simulation is carried out by solving the three-dimensional compressible Navier–Stokes equations. A free-stream Reynolds number (based on the free-stream velocity, density and viscosity coefficient and the diameter of the sphere) is set to be between 100 and 300, the free-stream Mach number is set to be between 0.2 and 2.0, and the dimensionless rotation rate defined by the ratio of the free-stream and surface velocities above the equator is set between 0.0 and 1.0. Thus, we have clarified the following points: (1) as free-stream Mach number increased, the increment of the lift coefficient due to rotation was reduced; (2) under subsonic conditions, the drag coefficient increased with increase of the rotation rate, whereas under supersonic conditions, the increment of the drag coefficient was reduced with increasing Mach number; and (3) the mode of the wake structure becomes low-Reynolds-number-like as the Mach number is increased.