预旋调节对离心泵空化影响的试验与数值模拟

Experimental and Numerical Investigations of Cavitation in a Centrifugal Pump with Pre-whirl Regulation

为探究前置导叶不同预旋角度对离心泵空化性能的影响规律,对带有自主设计前置导叶的IS 150-125-250型离心泵进行了空化性能试验,选用Zwart-Gerber-Belamri空化模型进行3D非稳态全流道空化流动数值模拟,结果表明:在一定的角度范围内,负预旋调节可以改善离心泵的空化性能,但超过某一角度后,空化性能将快速恶化;正预旋调节会恶化离心泵的空化性能,正预旋角度越大,恶化程度越明显。对不同预旋角度下叶轮内空泡率分布规律的分析发现,一定范围内的负预旋角会减小叶轮内空化区域,正预旋会增大叶轮内空化区域。

With the aim to explore the influence of inlet guide vane on the cavitation performance of centrifugal pump, the cavitation experiment on IS 150 - 125 - 250 centrifugal pumps with original design inlet guide vane has been conducted. Using the Zwart- Gerber- Belamri cavitation model, the 3D unsteady cavitation flow in centrifugal pump flow channels has been simulated. The result shows that the negative pre-whirl by guide vane regulation could improve the cavitation performance of centrifugal pump in a certain angle range, and the cavitation performance was deteriorated when the angle exceeds the certain value. The positive pre-whirl regulation deteriorated the cavitation performance of centrifugal pump, and it become even more serious with the increasing positive pre-whirl angle. The analysis of the vapor volume fraction distribution in impeller channels indicates that the negative pre-whirl angle reduced the cavitation zones in impeller, and the positive pre-whirl angle expanded the cavitation zones in impeller channels.