水流作用下圆柱体的涡激振动分析

以弹性支承的刚性圆柱体为研究对象,把流体对结构的作用力分成升力FL和流体反力FR两部分,建立了一种分析圆柱体涡激振动的方法。该方法把结构振动的微分方程转化为振幅与频率的代数方程,并给出了流体力系数的经验公式。实例计算表明,圆柱体的涡激振动主要受无量纲参数折算速度的控制,一般在折算速度Vr为4.0—9.0时,发生频率的锁定现象。该方法是预测圆柱体涡激振动的一种实用方法。

Analysis of Vortex-induced Vibration of a Cylinder in Steady Flow

The elastically supported rigid cylinder is taken as background to analyze the vortex-induced vibration of structures in steady flow. The fluid forces acting on structures are divided into lift F_ L and fluid reaction F_ R and a simplified method to analyze vortex-induced vibration of a cylinder is established. The method transfers the structural vibration differential equations into algebraic equations and the empirical formulae about fluid force coefficients is put forward. The results calculated indicate that vortex-induced vibration of cylinders is mainly controlled by reduced velocity, usually, the locking-in phenomenon occurs when the reduced velocity falls between 4.0 and 9.0. The method presented is a feasible one to predict vortex-induced vibration of cylinders.