不同叶顶间隙下斜流泵轮缘压力脉动特性的数值分析  

Numerical analysis of pressure pulsation characteristics of diagonal flow pump in adjacent area of tip clearance

作　　者：黎义斌[1,2] 毕祯[1] 李仁年[1,2] 胡鹏林[1] 周栋 

机构地区：[1]兰州理工大学能源与动力工程学院,甘肃兰州730050 [2]甘肃省流体机械及系统重点实验室,甘肃兰州730050 [3]湖南湘电长沙水泵有限公司,湖南长沙410205

出　　处：《水利学报》2015年第4期497-504,共8页Journal of Hydraulic Engineering

基　　金：国家科技支撑计划(2013BAF01B02);国家自然科学基金资助项目(51369015);甘肃省自然科学基金资助项目(1212RJYA001)

摘　　要：为了阐明斜流泵小流量工况下近叶顶间隙区域的压力脉动特性,揭示不同叶顶间隙RTC对斜流泵瞬态运行稳定性的影响,对斜流泵模型进行非定常数值模拟。选取叶顶间隙RTC分别为0、0.5、1和1.5 mm的4种方案,基于LES大涡模拟、SIMPLEC算法与结构化网格,通过压力脉动频谱分析,了解RTC与近叶顶间隙区域压力脉动的内在关系。结果表明,RTC引起的泄漏流与主流掺混加剧了叶顶间隙区域流动的不稳定性,降低了叶片的做功能力;较大的RTC可以有效减少叶顶间隙区域的高频压力脉动,但引起的泄漏流加剧;随着RTC的增大,叶轮近壁区压力脉动平均值逐渐减小,水力性能下降。斜流泵设计时,选取适当小的RTC可以提高斜流泵的整体水力性能。In order to clarify pressure pulsation characteristics of the diagonal flow pump in adjacent areas of tip clearance under small flow conditions, and reveal the effect of different blade tip clearance value RTC on transient stability, an unsteady numerical simulation was conducted for the diagonal flow pumps. Four plans of diagonal flow pumps were selected with different RTC values of 0, 0.5, 0.75 and lmm as study objects, based on the large eddy simulation （LES） approach, SIMPLEC algorithm and block structured grids. By analyzing pressure pulsation spectrum, the internal relation between RTC and pressure pulsation of adja- cent areas of tip clearance has been realized. The results show that the leakage flow caused by RTC mixing with main flow aggravates the instability of the flow on tip clearance areas, reducing the performance abili- ty of impeller blades; the greater RTC can reduce high frequency pressure pulsation of blade tip areas, but give rise to leakage rate aggravation; with RTC increasing, the average value of pressure pulsation on impel- ler near wall regions decreases gradually, and hydraulic performance declines. Choose a proper small Rrrc at design time can improve overall hydraulic performance of diagonal flow pumps.

关 键 词：斜流泵 叶顶间隙 频谱分析 压力脉动 数值分析 

分 类 号：TH313[机械工程—机械制造及自动化]