高分辨率TVD-FVM方法求解二维圆柱受迫振动问题

Two-dimensional simulation on forced oscillations of a circular cylinder using high-resolution TVD-FVM method

该文基于RANS方程,结合SST k-ω湍流模型,用单元速度向量转化法基础上的TVD格式对不可压缩流进行有限体积求解。研究雷诺数10 000,无量纲振幅0.3-0.5,无量纲频率0.70-1.40的圆柱受迫振动问题,结果表明:升力系数随无量纲频率变化规律与他人实验及数值结果拟合良好,成功捕捉到升力系数相位跳跃现象;对激振力系数、涡力系数、漩涡脱落形态及漩涡脱落频率进行深入分析,从能量角度验证转变(transition)现象。通过分析受迫振动激振力系数随无量纲频率变化规律,划分出激振区的无量纲频率范围,以利于半经验模型的快速VIV分析。对涡力及其相位进行分析,发现在转变后,涡力系数的数值大于升力系数,说明在振动频率较大时,惯性力较大,尽管惯性力不影响能量系数变化,但会加大涡力系数。

In this paper, flow around an oscillating cylinder was simulated by high-resolution TVD-FVM method to solve the Reynolds-averaged Navier-Stokes equations coupled with the SST k-ω modal. This research focused on an oscillating circular cylinder at Reynolds number 10 000, dimensionless amplitude 0.3-0.5 and dimensionless frequency 0.70-1.40. It showed that as the oscillating frequency increased, lift coefficient and phase angle both presented a jump which agreed well with the previous experimental and numerical results.It showed that energy transition occurred between two distinctly different wake states according to the changes of excitation force, vortex force, wake mode and vortex shedding frequency performance. This paper provided excitation force coefficient as a criteria to divide excitation and damping zone which would be helpful for the semi-empirical VIV analysis. After transition occurred, vortex force was larger than lift force which related to the increase of mass coefficient.Although the mass coefficient had no affect on energy coefficient, it would enlarge the vortex coefficient.