高抗气蚀离心泵内流场数值模拟研究（英文）

Numerical Investigation of Internal Flow in Cavitation Resistant Centrifugal Pump

本文以同一工况下具有相同进出口尺寸的离心泵模型为对象,基于数值模拟的方法研究了子午面轮廓和长短叶片对离心泵的气蚀性能和水力性能影响。遵循抗空化设计准则提出有别于普通离心泵的三种高抗气蚀离心泵,其一具有驼峰型过水断面曲线,最大值在叶片前缘处以降低前缘冲击损失,减少空化影响。其二采用诱导轮叶轮一体化设计,安置分流叶片,长叶片在进口处螺旋形前伸,提前做功,使低压点前移。其三结合以上两种设计手段综合提高抗气蚀性能。采用多相流CFD模型预测三种模型泵在设计工况下的气蚀性能叶片载荷与气液两相分布间,并在无量纲空化数下分析了其气蚀性能。结果显示进口延长的螺旋形长叶片形成了类似诱导轮的效果,降低了整个叶轮对空化影响的敏感性。另一方面,单纯地扩展子午面流道虽然可以显著提高扬程与空化性能,但是却对整体效率产生了不利影响。

This paper presents numerical research on the cavitation resistive property and hydraulic performance of centrifugal pumps with different meridian plane profile, designed with same import and export dimensions. All the three impellers adopt distinct anti-cavitation design philosophy, which leads to their distinguished appearance feature from ordinary centrifugal impeller. One of them has a hump-type curve in cross section area where the maximum value lies on the position of leading edge of blades. The other one is a inducer-and-impeller-combined type with split blades. For the third impeller, it integrates the main feature of the first two impellers.Cavitation performance of these three impellers is simulated in designed flow rate through multi-phase CFD method and compared with dimensionless cavitation coefficient. The blade loads and gas-liquid two-phase distribution are calculated and acquired. The results show that the long spiral blades inlet extension play a effective role as inducer to drop the sensitivity to cavitation impact for the whole impeller. On the other side, an expanded merdional passage in this kind of impeller have an adverse impact on the efficiency in designed flowrate but change the head and cavitation characteristics.