离心泵流致振动分析方法

Analysis Method of Flow Induced Vibration of Centrifugal Pump

分析了离心泵由动静干涉诱导的整流场压力脉动导致的结构振动。首先,对离心泵的流致振动方法进行了研究,设计了流场载荷至结构的传递方式;然后,基于计算流体动力学,对离心泵的两个额定工况进行了流场稳态计算;之后,在稳态计算的基础上对工况2进行了瞬态计算,提取了流场瞬态载荷;最后,基于计算结构动力学,进行了在流场载荷作用下的离心泵结构的流致振动响应计算。结果表明,两个额定工况的扬程和效率计算值与额定值吻合较好;压力脉动频率以290 Hz(叶频)为主,叶轮集中力频率以48.33 Hz(轴频)为主;结构振动响应频率主要体现为流场载荷频率及结构固有频率,其中,流场激励频率与结构固有频率相近导致振动幅值相对较高。

The structure vibration of centrifugal pump caused by pressure pulsation of entire flow field induced by dynamic and static interference is analyzed.Firstly,the flow induced vibration method of centrifugal pump is explored,and the transfer mode of flow field load to structure is designed;secondly,based on computational fluid dynamics,the steady flow field of centrifugal pump under two rated conditions is calculated;thirdly,based on the steady-state calculation,the transient calculation of condition 2 is carried out,and the transient load of the flow field is extracted;finally,based on computational structural dynamics,the flow induced vibration response of centrifugal pump structure under flow field load is calculated.The results show that the calculated values of head and efficiency under the two rated conditions are in good agreement with the rated values;the pressure fluctuation frequency is mainly 290 Hz(blade frequency),and the impeller concentrated force frequency is mainly 48.33 Hz(shaft frequency);the vibration response frequency of the structure is mainly reflected in the load frequency of the flow field and the natural frequency of the structure.The excitation frequency of the flow field is similar to the natural frequency of the structure,resulting in a relatively high vibration amplitude.