流体诱导弹性管束振动响应数值分析

Numerical analysis on flow-induced vibration responses of elastic tube bundle

基于流固耦合问题的弱耦合法,研究弹性管束不同流速的壳程或/和管程流体诱导下的振动响应。研究表明,流体诱导振动幅值随壳程或/和管程流速的增加而增加。与相同管程流速条件相比,壳程流体引起的振幅较大。随壳程流速增加监测点振动频率增加;随管程流速增加监测点振动频率基本不变。壳、管程流体耦合诱导的振动位移曲线与仅壳程流体诱导的振动位移曲线类似,说明弹性管束工作过程中的振动主要由壳程流体诱导。流体诱导的振动频率接近管束第一阶固有频率时,监测点在y,z方向振幅逐渐趋于峰值。流体诱导弹性管束的振动主要表现为面内振动。

Based on the weak coupling method for fluid-structure interaction, the vibration characteristics of the elastic tube bundle subjected to shell-side or/and tube-side cross flow were studied under different water inlet velocities. The numerical results show that the flow-induced vibration amplitude increases with increasing the shell-side or/and tubeside water inlet velocity. However, the amplitude of shell-side flow-induced vibration is greater than that of tube-side flow- induced vibration under the same water inlet velocity. The flow-induced vibration frequency at the monitoring point increases with increasing the shell-side water inlet velocity, and maintains substantially unchanged as the tube-side water inlet velocity increases. Moreover, the displacement curves of the vibration induced by the coupled shell-side and tube- side flow＂ are similar to those induced by the single shell-side flow, and it is indicated that the vibration is mainly induced by the shell-side water. The vibration amplitudes at monitoring points in y and z directions are gradually approaching the peak when the flow-induced vibration frequency is close to the first natural frequency of the elastic tube bundle. The elastic tube bundle subjected to shell-side cross flow behaves mainly as in-plane vibration.