基于CFD的轴流泵空化特性预测  

Prediction of cavitation performance of axial-flow pump based on CFD

作　　者：杨正军[1] 王福军[1] 刘竹青[1] 张志民[2] 

机构地区：[1]中国农业大学水利与土木工程学院,北京100083 [2]中国水利水电科学研究院,北京100038

出　　处：《排灌机械工程学报》2011年第1期11-15,共5页Journal of Drainage and Irrigation Machinery Engineering

基　　金：中央高校基本科研业务费专项资金资助项目(15059201;TG0901)

摘　　要：基于空泡动力学和汽液两相流理论,应用计算流体动力学(CFD)技术模拟了轴流泵在不同进口压力条件下(包含轴流泵中未发生空化和发生剧烈空化的多种情况)的流场,研究了随着空化发生、发展速度场及压力场变化过程,并对轴流泵能量特性、空化性能进行了预测.结果表明,在非空化条件下,CFD计算可较准确地预测水泵扬程等能量特性,预测值与试验值相差在2%以内;在空化条件下,CFD计算成功地捕获到了空化发生、发展过程;流场中空化发生直接影响叶轮叶片上的压力分布,进而影响水泵的扬程、轴功率等外特性;在发生空化条件下,导叶背面进水边靠近轮缘位置也会出现空化现象;在叶轮各个通道内空化区域分布相似,轴对称性明显,而导叶体内各个通道的空化区域分布差异大,呈明显的非轴对称分布,该非轴对称性的空化区域也是空化造成轴流泵不稳定运行的一个因素.The flow field in an axial-flow pump at different inlet pressure conditions including cavitating and non-cavitating conditions was simulated by using the computational fluid dynamics（CFD） approach based on theory of bubble dynamics and steam-liquid two-phase flow. The velocity field and pressure distribution were analysed during cavitation progress and the pump characteristics were predicted. The results show that under the non-cavitating condition, the pump head-flow relationship is well predicted with an inaccuracy within 2%. While under the cavitating condition, the cavitation occurring and developing processes are captured successfully by CFD simulation. The cavitation directly affects the pressure distribution on impeller blade surfaces, and also results in change of the pump head and power characteristics. Under the cavitation condition, the cavitation area can be found at the leading edge of the guide vane suction sides. Similarity of the cavitation distribution are found among the different impeller passages. But significant differences of the cavitation distribution are revealed among the different guide vane passages, which is one of the primary factors that result in unstable operation of an axial-flow pump.

关 键 词：轴流泵 空化 性能预测 计算流体动力学 

分 类 号：S277.9[农业科学—农业水土工程] TH312[农业科学—农业工程]