研究了雷诺数Re=200, 1000, 线速度比$\alpha =0.5$,

研究了雷诺数Re=200, 1000, 线速度比$\alpha =0.5$, 2.0, 4.0, 强迫振荡频率$f_{s}=0.1\sim 2.0$情况下的旋转振荡圆柱绕流问题. 通 过基于非结构同位网格有限体积法对Navier-Stokes方程进行数值求解. 对流项、扩 散项和非恒定项的离散格式均具有二阶精度，利用SIMPLE算法处理压力-速度耦合. 计算得到了作用力系数随不同控制参数的变化规律. 通过对升力系数的频谱分析得到 自然脱落频率和强迫振荡频率下的作用力振幅. 通过对不同频率作用力幅值的分析， 得到频率之间的竞争关系，进而定量地给出了不同尾迹涡脱落模式的分区图.

FLOWS PAST A ROTATING CIRCULAR CYLINDER BY FVM BASED ON UNSTRUCTURED MESHES

The unsteady flow past a circular cylinder which starts translating and rotary oscillating impulsively from rest in a viscous fluid is investigated at Reynolds numbers $Re=200$ and 1000, rectilinear speed ratios $\alpha =0.5$, 2.0 and 4.0, and for forced oscillating frequencies $f_{s}$ between 0.1 and 2.0. Numerical solutions of the Navier-Stokes equations are obtained by a finite volume method based on unstructured colocated meshes. The discretized schemes of the convective fluxes, diffusive fluxes and unsteady term are all of second-order accuracy. The SIMPLE algorithm is adopted to deal with the pressure-velocity coupling. The varieties of force coefficients with the control parameter are obtained after the discussion. The amplitudes of lift coefficients at natural shedding frequency and forced oscillating frequency respectively are determined by the amplitude spectra analysis, which show clearly the competitive relationship between the two frequencies. Based on this relationship, the region of the classification of flow structure modes is given at last.