三维流体诱发振动的理论模型与数值模拟  

Theoretical Model and Numerical Simulation of Three-Dimensional Flow Induced Vibration

作　　者：张楚华[1] 

机构地区：[1]西安交通大学流体机械及压缩机国家工程研究中心,西安710049

出　　处：《西安交通大学学报》2007年第5期512-516,525,共6页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金(10572113);教育部新世纪优秀人才支持计划资助项目(NCET-06).

摘　　要：建立了三维流体诱发振动的理论及数值模型,采用任意拉格朗日-欧拉框架下的三维非定常Navier-Stokes方程组及波动方程组,分别描述了流体的流动及结构振动．流动及振动控制方程组分别采用基于非结构化运动网格上的有限体积法和有限差分法求解．对刚性、受限振动及自由振动的三维圆柱体进行了数值计算．结果表明:圆柱的自由振动基本上为Strouhal型涡诱发振动,即每个截面按“8”字型轨迹运动,且横向振幅远大于流向振幅,计算结果与现有的实验及数值解吻合较好．首次采用流体诱发振动模型对极限环振动模式进行了定量分析,发现在圆柱中间截面附近高频气动力对振动起阻尼作用,而在端面附近气动力与位移间的稳定相位差对振动起激励作用．A theoretical and numerical model for three-dimensional flow induced vibration was proposed. The theoretical model consists of three-dimensional unsteady Navier-Stokes equations under arbitrary Lagrange-Euler frame for fluid flow, and wave equations for structural vibration. The numerical method is finite volume method on unstructured moving mesh for fluid flow and finite difference method for structural vibration. The proposed method is applied to rigid stationary, constrained vibrating and freely vibrating circular cylinders, respectively. For the rigid case, the present results fit the available data well. For the flexible case, the cylinder vibrates freely as Strouhal-type mode in which each cylinder .section is in motion along ＂8＂ shaped trajectory. The limiting cycle vibration mode was interpreted for the first time using flow induced vibration model. At the midspan region, the fluid force plays a damper role in the cylinder vibration mainly due to the third harmonic component, while at the near wall region, the relative stable phase difference between the fluid force and the vibration displacement plays an actuator role in the vibration.

关 键 词：流体诱发振动 圆柱 极限环 NAVIER-STOKES方程 波动方程 非结构化运动网格 

分 类 号：O357[理学—流体力学]