基于任意拉格朗日-欧拉描述法及刚性模型和计算网格同步运动的动网格技术,数值模拟了作竖弯或扭转谐振动的平板绕流场.通过计算一个运动周期内作用在平板上的总功,分析了理论平板的颤振机理.研究表明仅有竖弯自由度或扭转自由度的平板不可能发生单.自由度颤振.计算了中央开槽20%平板的颤振导数.通过对一设想的大跨度桥梁进行二自由度颤振分析,显示平板中央开槽能显著提高其颤振稳定性.最后从气动机理上解释了平板开槽能提高颤振稳定性的原因.
Based on the arbitrary-Lagrangian-Eulerian descriptions for a rigid oscillating body and by using the moving mesh technique, the fluid field around the ideal thin plate (ITP) in sinusoidally heaving or pitching motions was simulated by numerical method. After evaluating the total work acting on the ITP by the airflow during an oscillating cycle, the flutter mechanism of the ITP was discussed. Results showed that flutter instabilities would not occur for the ITP with only one degree-of-freedom. With the identified flutter derivatives of the slotted ITP with slot ratio of 20%, a two-degree-of-freedom flutter analysis was performed based on an assumed long-span bridge. In addition,numerical simulations were also carried out to investigate the flutter mechanism of the slotted ITP. It was found that a central slot on the ITP could largely reduce the total work acting on the ITP by the airflow, and a certral slot made the ITP more stable against flutter.