Experimental investigation and numerical analysis of unsteady attached sheet- cavitating flows in a centrifugal pump

• Published in: Journal of hydrodynamics. Series B Vol. 25; no. 3; pp. 370 - 378
• Main Author: 刘厚林 刘东喜 王勇 吴贤芳 王健 杜辉
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2013; Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, zhengjiang 212013, China
• Subjects: attached sheet cavitation; bubbles; Cavitation; centrifugal pump; Centrifugal pumps; Computer simulation; FBM模型; Filter-Based Mode (FBM); Flow coefficients; high-speed camera; Impellers; Mathematical models; modified Zwart model; prediction; Unsteady; vapors; Volume fraction; 不稳定; 实验; 数值分析; 气蚀现象; 离心泵; 空泡流; 过滤模型; high-speed camera; modified Zwart model; attached sheet cavitation; centrifugal pump; Filter-Based Mode (FBM)
• ISSN: 1001-6058
• DOI: 10.1016/S1001-6058(11)60375-3

This paper studies the attached sheet cavitation in centrifugal pumps. A pump casted from Perspex is used as the test subject. The cavitation bubbles were observed in the entrance of the impeller and the drops of the head coefficients were measured under different operating conditions. A Filter-Based Model （FBM）, derived from the RNG k-e model, and a modified Zwart model are adopted in the numerical predictions of the unsteady cavitating flows in the pump. The simulations are carded out and the results are compared with experimental results for 3 different flow coefficients, from 0.077 to 0.114. Under four operating conditions, qualitative comparisons are made between experimental and numerical cavitation patterns, as visualized by a high-speed camera and described as isosurfaces of the vapour volume fraction ctv = 0.1. It is shown that the simulation can truly represent the development of the attached sheet cavitation in the impeller. At the same time, the curves for the drops of the head coefficients obtained from experiments and calculations are also quantitatively compared, which shows that the decline of the head coefficients at every flow coefficient is correctly captured, and the prediction accuracy is high. In addition, the detailed analysis is made on the vapour volume fraction contours on the plane of span is 0.5 and the loading distributions around the blade section at the midspan. It is shown that the FBM model and the modified Zwart model are effective for the numerical simulation of the cavitating flow in centrifugal pumps. The analysis results can also be used as the basis for the further research of the attached sheet cavitation and the improvement of centrifugal pumps.