无变形网格下运动参考系求解平动流固耦合问题

Translational fluid-structure interactive vibration simulation using fixed grid and moving reference frame

为模拟平动涡激振动,采用一种无变形网格的计算方法。通过运动参考系模拟整个求解域的运动,结合非结构网格下高精度算法,在NS方程中引入运动参考系引起的对流项及采用新的边界处理方式,通过构造合理的计算求解域,对低雷诺数下(Re=200)圆柱涡激振动进行了模拟,得到了圆柱涡激振动振幅以及详细流场结构,与实验结果和数值结果相比都得到了很好的一致性。并对不同阻尼比、频率比等参数进行研究,详细对比了不同振幅下尾流结构特征。结果证明了该计算方法是可行的、准确的。

A new approach using fixed gird was adopted to simulate the translational motion of solid walls. Combining with a high-accuracy and high-stability algorithm in the condition of non-structured mesh, a solution over entire computational domain was achieved by use of the moving reference frame, which must be taken to consider the convection term of N-S equation. Meanwhile, the boundary conditions of the solid wall were specially treated with a new method. A reasonable computational domain was established to simulate the translational motion of a circular cylinder in the fluid with low Reynolds number of 200 and the vibration amplitude of the cylinder and the detailed flow field structure were obtained. Changing the ratio of the cylinder natural frequency to its wake vortex shedding frequency and the structural damping ratio, the vortex induced vibration amplitudes and the wake flow structures in the condition of different vibration amplitudes were compared and analysed. The results show that the computational method provided tends to be feasible and accurate. © 2017, Editorial Office of Journal of Vibration and Shock. All right reserved.