内外流作用下的U型管流致振动分析

Analysis of Flow Induced Vibration of U-tube Under Internal and External Flow

为了探究U型管在内、外流体共同作用下的流致振动特性,基于ANSYS Workbench平台采用单向流固耦合方法,对外流为空气及内流为水联合作用下的单根U型管的振动特性进行了研究。结果表明,系统主要激励来自外流,外流会影响系统稳态响应的振动幅值及频率;内流对平均位移及固有频率影响则更为显著,内流对U型管各阶固有频率的降低幅度约为11.9%;由于内、外流体力的作用方向存在差异,每一个外流流速都存在一个最佳减振内流流速,某些流速组合(例如vout=10 m/s,vin=6 m/s时)可以使U型管的平均位移降低90%以上。

In order to explore the fluid-induced vibration characteristics of U-tube under the combined action of internal and external fluids,the vibration characteristics of a single U-tube under the combined action of external flow of air and internal flow of water are studied based on ANSYS Workbench by using a one-way fluid�structure interaction method.The results show that the main excitation of the system comes from the external flow,which will affect the vibration amplitude and frequency of the steady-state response of the system;the internal flow has a more significant impact on the average displacement and natural frequency,and the reduction of the internal flow on the natural frequency of the U-tube of each order is about 11.9%;due to the differences in the action direction of the internal and external fluid forces,there exist an optimal damping internal flow velocity for each external flow velocity.Under certain flow velocity combinations(such as vout=10 m/s,vin=6 m/s),the average displacement of the U-tube can be reduced by more than 90%.