带有前置导叶离心泵空化性能的试验及数值模拟

Experiment and Numerical Simulation of Cavitation Performance for Centrifugal Pump with Inlet Guide Vane

为分析前置导叶对离心泵空化性能的影响,在不同流量下开展带有前置导叶离心泵的空化性能试验,得到无导叶、导叶预旋角±12°时的离心泵空化性能曲线。空化性能试验结果表明,离心泵的临界空化余量LNPSHc随流量的增大近似线性增大。基于均相流假设的完全空化模型,考虑空化流可压缩性的影响修正RNGk-ε湍流模型,采用SMPLEC算法,数值求解雷诺平均的Navier-Stokes方程,模拟离心泵安装前置导叶前后不同工况下的全流道空化流动。计算得到的H-LNPSHa曲线与试验数据吻合较好,验证计算方法的准确性。基于数值模拟结果,分析不同工况下叶轮内部空泡体积率的分布规律,发现前置导叶预旋调节对离心泵叶轮空化性能的影响较小,并能有效改善叶轮进口流态,使压力分布更均匀。

To analyze the effect of inlet guide vane on the cavitation performance of centrifugal pump,cavitation performance test of centrifugal pump with different flow rate is carried out.The cavitation performance curves of centrifugal pump,on the conditions of no guide vane and the guide vane angles of ±12°,are obtained from experiment.Based on the full cavitation model using the homogeneous flow model supposition,considering the compressibility effect on cavitating flow to modify the RNG k-ε turbulence model,the Navier-Stokes equation is solved with SIMPLEC algorithm to simulate full passage cavitation flow of centrifugal pump without and with inlet guide vane under various conditions.The calculated H-LN PSHacurves agree well with the experiment data,and the accuracy of the method is verified.Based on the result of numerical simulation,the distribution of vapor volume fraction in impeller under various conditions is analyzed,the inlet guide vane pre-whirl regulation has little influence on cavitation performance of centrifugal pump impeller,and can improve impeller inlet flow pattern,thus resulting in more uniform pressure distribution.