Abstract: The producing and development process of the vortex shedding from the circular cylinder were simulated by the software ANSYS CFX，and the calculative example was also given． The Navier-Stokes ( N-S) equation was dispersed by finite volume method，and SIMPLE method was used to solve the discrete N-S equation． The distribution of surrounding pressure coefficient around circular cylinder surface，the drag coefficient，the lift coefficient and Strouhal number of the circular cylinder were calculated and analyzed． The influence of two-dimensional fluid-structure coupling on the flow characteristics around a circular cylinder was obtained． The results of calculation show that because the cylinder is influenced by the water flow，the cylindrical lift and wake flow characteristics show the periodic change，and single frequency vibration also occurs．

Key words: flow around a cylinder, two-way fluid-solid coupling, three-dimensional numerical simulation, Ｒeynolds number; drag coefficient, lift coefficient

摘要： 考虑双向流固耦合并利用软件ANSYS CFX 模拟了圆柱表面涡脱的产生和变化过程，结合工程实际给出了计 算实例，采用有限体积法对流体力学控制方程Navier-Stokes 进行离散，用SIMPLE 方法求解，分析计算了圆柱表面周 向压力系数分布情况及圆柱的阻力系数、升力系数及Strouhal 数，得到了流体与结构物相互作用对圆柱绕流特性的 影响。结果表明: 由于圆柱受到水流的作用，圆柱的升力及尾流特征显示周期性变化，并出现单一频率振动。

关键词: 圆柱绕流, 双向流固耦合, 三维数值模拟, 雷诺数, 阻力系数, 升力系数