斜拉索风雨振-实验与数值模拟混合子结构方法

Hybrid approach combining experiment and CFD numerical Simulation for rain-wind-induced vibration of a stay cable

人工模拟降雨条件下,斜拉索风雨激振的非定常气动力难以测试,本文提出结构风致振动的实验与数值模拟的混合子结构方法,将结构和流场分为2个子结构,将实验获得的结构振动作为动边界施加在流场子结构,仅对动边界的绕流场进行CFD数值模拟.首先通过圆柱涡激振动验证混合子结构方法的可行性及精度;然后采用混合子结构方法,计算斜拉索风雨激振的气动力并施加到斜拉索上,得到斜拉索振动响应并与实验结果比较.结果表明混合子结构方法能够准确获得斜拉索风雨激振的气动力时程.

As the aerodynamic forces are inconvenient to be measured in the wind tunnel tests of rain-wind-in-duced vibration（RWIV）of a stay cable under artificial simulation of rainfall,this paper presents a hybrid ap-proach combining experiment and computational fluid dynamics（CFD）numerical simulation for RWIV of a stay cable.The stay cable（including the rivulet）and the flow field are considered as two substructures in the entire system,and the motions of stay cable and rivulet measured through wind tunnel tests are considered as known boundary condition and applied to the flow field.The flow around the moving boundary is then numeri-cally simulated by the Fluent CFD code.First,the feasibility and precision of this approach are verified through the vortex-induced vibration of a circular cylinder,and then the approach is used to study the RWIV of the stay cable.The transient aerodynamic lift and drag coefficients are calculated and applied to a single de-gree of freedom model（SDOF）of the stay cable.The comparison is carried out between the oscillation re-sponses of the SDOF model and experimental results,which indicate that the hybrid approach combining ex-periment and CFD numerical simulation can effectively simulate the transient aerodynamic coefficients of stay cable suffering from the RWIV.