基于流固耦合的泵组管系振动分析

为了找出管系的振源以及产生的原因,采用有限元法计算管系的模态和谐响应.管壁选用壳单元划分,管壁内流体则采用流体单元,建立了包括泵组的三维空间管系的流固耦合模型,考虑管系的柔性支撑边界条件,进行迭代求解.计算表明,在水泵电机二倍转频48.3Hz附近,管系频率较集中,各测点频率响应数值均较大,50Hz时3号泵出水管垂直方向最大位移响应达13.96mm,计算结果与LMS动态测试系统的测试结果一致.泵组管系的振动原因是由于泵的周期性运动,造成管道内压力和流量的脉动,其变化频率和管系固有频率接近从而引起了共振.

Vibration analysis on a pipe system of pumps based on fluid-structure interaction

A pipe system of pump set and three dimensional pipes were investigated in the modal and harmonic response using FEM to find its vibration source and reason. The fluid-structure interaction model is built,of which shell elements was applied to the pipe,fluid elements was for the fluid and flexible support boundary conditions were considered,and solved iteratively. The results show that natural frequencies of the system are located nearby 48. 3 Hz,which is of two times of the rotating frequency,and at which the displacement responses at tested points are larger. At the frequency of 50 Hz,the maximum displacement response is of 13. 96 mm at the outlet pipe of No. 3 pump. They are consistent with the data tested by LMS dynamical test system. Obviously,the heavy vibration of the pipe system is a resonance caused by the periodical change in pressure and flow rate from the pump.