超临界雷诺数下旋转圆柱绕流的三维大涡

Three-dimensional large eddy simulation of flow around a rotating circular cylinder under supercritical Reynolds number

超临界雷诺数状态下,圆柱下游紊流边界层的分离会导致RANS算法在求解过程中遇到一定的困难,而在工程实际中,特别是在海洋能发电塔架、风力机钝尾缘处发生的钝头体绕流均处于超临界雷诺数状态。因此,文章基于Fluent模拟软件使用大涡模拟(LES)方法,对超临界雷诺数为3.5×106时,不同比转速的旋转圆柱进行三维数值模拟,并分析其水动力学特性。文章将模拟结果与相关文献的研究结果进行比较,验证了模拟结果的准确性。研究结果表明,由马格努斯效应产生的升力对旋转圆柱下游卡门涡街的发展具有抑制作用,当比转速大于10时,旋转圆柱下游不再发生有规律的卡门涡街。

Under the supercritical Reynolds number, the separation of the turbulent boundary layer in the downstream of the cylinder leads to some difficulties in the process of solving the RANS algorithm. However, in engineering practice, most of the flow around a bluff body occurs with a high supercritical Re especially in ocean power generation tower and the blunt trailing edge of wind turbines. Based on Fluent software and its large eddy simulation（LES） method, three dimensional numerical simulation of rotating cylinder was carried out with different rotating speed ratio under Re=3.5×106. Then, the simulation results were compared with those of the related literatures, and the accuracy of the simulation results was verified. The results show that the lift caused by the Magnus effect has an inhibitory effect on the development of the downstream in the rotation of the cylinder. When the rotational speed is greater than 10, the regular Karman vortex street is no longer occurring in the downstream of the rotating cylinder.