不同叶片数对低比转速离心泵压力脉动的影响  

Impact of number of blade on pressure fluctuation in low-specific-speed centrifugal pump

作　　者：刘宜[1] 陈文鹏[1] 肖丽倩 刘明[1] 

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

出　　处：《兰州理工大学学报》2016年第3期62-66,共5页Journal of Lanzhou University of Technology

基　　金：甘肃省自然科学基金(ZS022-A25-018)

摘　　要：为了研究不同叶片数对压力脉动的影响,在保证叶轮其他几何参数不变的情况下,将叶片数设计为4、5、6三种情况,采用FLUENT软件、RNGk-ε湍流模型和滑移网格技术,对低比转速离心泵进行了三维非定常数值模拟,分析了不同叶片数对蜗壳隔舌、蜗壳-叶轮间隙以及蜗壳扩散段内压力脉动的影响.结果表明:各个叶片数泵在三个监测点压力脉动频率均以叶片通过频率为主,且在隔舌处压力脉动幅值变化最大;6叶片数泵在小流量下,隔舌处压力脉动幅值变化均小于4、5叶片数,其最大脉动幅值约为静压均值的9%左右;5叶片数泵隔舌处,在0.6、1.4倍设计流量时压力脉动幅值明显大于设计流量下的幅值,约为设计工况下幅值的2倍和2.4倍;4叶片数泵在1.0、1.4倍的设计工况下,隔舌处的压力脉动变化最大,其最大幅值约为设计叶片数的1.29倍和1.4倍.在不同叶片数时,蜗壳扩散段和蜗壳-叶轮间隙内压力脉动变化相对隔舌处较小.In order to study impact of number of blade on pressure fluctuation in low-specific-speed centrifugal pump,the impellers of the pump with 4,5and 6blades were designed while rest geometric parameters of pump remain unchanged.Their three-dimensional turbulence flow was numerically simulated with software FLUENT,RNGk-εturbulence mode and sliding mesh skill and the influence of number of blade on pressure fluctuation at the volute tongue,within the gap between volute and impeller,and in volute diffusing section.The result shows that the passing frequency of blade would＂dominate that of pressure fluctuation at these monitoring points in the pump with different number of blade,and the greatest amplitude change of pressure fluctuation would take place at the volute tongue.Under small design flow rate,the amplitude change of pressure fluctuation at volute tongue of the pump with 6blades would be less than that with 4or 5blades,and its greatest pressure pulsation amplitude would be about 9% of the average static pressure.In the case of 60% or 140% design flow rate,pressure pulsation amplitude at volute tongue of pump with 5blades would be obviously greater than that in the ease of design flow rate,being about 2and 2.4times respectively of that of the latter.In the case of 100% or 140% design flow rate,the greatest change of pressure fluctuation would take place at the volute tongue in the pump with 4blades,being about 1.29 and 1.4respectively times of that of pump with design number of blade.The pulsation amplitude within the gap between volute and in impeller and in volute diffusing section would be less than that at the volute tongue with different number of blade.

关 键 词：低比转速离心泵 叶片数 压力脉动 

分 类 号：TH311[机械工程—机械制造及自动化]