离心泵叶轮出口宽度对泵腔内压力脉动分布的影响

Effects of impeller outlet width on pressure pulsation in two side chambers of centrifugal pump

在试验和数值模拟相互验证的基础上,开展叶轮出口宽度对离心泵泵腔内压力脉动分布影响的研究.通过试验和数值计算获得离心泵的外特性、泵腔内静压分布、泵腔内压力脉动分布及泵体表面的压力脉动幅值分布,并进行对比分析,结果表明:前泵腔内静压和压力脉动幅值随出口宽度的增大而增大,随半径的减小而增大;后泵腔内静压和压力脉动随出口宽度和半径的变化不十分明显.综合考虑外特性和压力脉动,在比转数ns=97时叶轮出口宽度与叶轮出口直径之比应小于0.06;为了使压力脉动在泵腔内有效地衰减,出口宽度与前腔间隙的比值在1.81附近时最佳.研究结果可用于指导离心泵叶轮的优化设计.

The effects of impeller outlet width on pressure pulsation in two side chambers of a centrifugal pump are studiedBased on the mutual authentication between experiment and numerical simulation.The pump performance curves are measured and predicted with CFD simulation at different impeller outlet widths,the fluid static pressure and pressure pulsation as well as pulsation amplitude distributions in both side chambers are obtained and analyzed comparatively across the different width cases.The predicted performance curves are in good agreement with the experimental data.It is turned out that the static pressure and pressure pulsation in the front side chamber ascend with the enlarging outlet width and reducing radius.However,there is no significant change in them with variable outlet width and radius in the rear side chamber.Based on a trade-off between pump performance and pressure pulsation in the chambers and volute,the ratio of the impeller outlet width to the impeller diameter shouldBe less than 0.06 at the specific speed ns= 97.In order to make the pressure pulsations effectively decayed in the side chambers,the best ratio of the impeller outlet width to the gap of the frontside chamber shouldBe about 1.81.The results can be used to guide the optimal design of the impeller of centrifugal pumps.