为分析蜗壳进口宽度对离心泵非定常性能的影响，以一台比转速为126的离心泵为研究对象，采用ANSYS CFX软件的标准k－ε湍流模型对同一叶轮、不同蜗壳进口宽度（56、63、66.5和70 mm）时，不同流量工况（0.8~1.2设计流量）条件下泵的外特性、内部流场以及压力脉动进行研究。结果表明：在设计流量下，适当改变蜗壳进口宽度对离心泵的扬程、效率影响不大；但随着蜗壳进口宽度的增大，蜗壳隔舌处的湍动能增大并向扩散段延伸；同时，蜗壳隔舌处压力脉动的压力值增大了4.2%，压力脉动幅值增大了3.4倍。设计时为提高中比转速离心泵的综合性能，应取蜗壳进口宽度为叶轮出口直径的1.8倍。

To study the effect of the volute inlet width on the unsteady performance of centrifugal pumps,a centrifugal pump with a specific speed of 126 was taken as the research object.The standard k-ε turbulent model in ANSYS CFX software was used to simulate the external characteristics,internal flow field and pressure pulsations of the pump with the same impeller,different volute inlet widths (56 mm,63 mm,66.5 mm and 70 mm) and at different flow rates (0.8 to 1.2 times of the design flow rate).The results show that the appropriate changes of volute inlet width have a little effect on the lift and efficiency of the centrifugal pump at the design condition.As the inlet width increases,the turbulent energy at the volute tongue increases and extends toward the diffuser.Meanwhile,the pressure value of the pressure pulsation at the volute tongue is increased by 4.2%,and the pressure pulsation amplitude is increased by 3.4 times.To improve the comprehensive performance of the medium specific speed centrifugal pump,the volute inlet width should be 1.8 times of the impeller outlet diameter.

TH311

四川省教育厅项目(18ZB0560)；西华大学研究生创新基金项目(ycjj2018038)