双吸离心泵叶片区压力脉动特性分

采用大涡模拟方法(LES)和滑移网格技术,对双吸离心泵不同工况下的内部三维非定常湍流流场进行了数值模拟,研究了叶轮区域流场特性及叶片表面的压力脉动特性.结果表明,叶片区的压力脉动频率以叶轮转频为主,且压力脉动幅值随着偏离设计工况程度的增大而显著增加,尤其是在小流量工况Q/Qd=0.62下,压力脉动变化幅度最大,约为最优工况的3倍;设计工况下,叶片头部区域压力脉动幅值最大,约为静压均值的14％,分别比叶片正面中心处大86％,比叶片背面中心处大169％.

Pressure Fluctuations of the Impeller in a Double suction Centrifugal Pump

The large eddy simulation method with sliding mesh technology was used to investigate unsteady flow characteristic in a double-suction centrifugal pump on different operating conditions. The unsteady flow in the impeller, especially on the blade surface was focused on. The results showed that the rotating frequency dominated the pressure fluctuations in the impeller at design and off-design conditions. The amplitude of the pressure fluctuation became higher when the flow rate was farer from the design flow rate, especially at Q/Qd=0.62 that the maximum amplitude occurred, nearly three times of design condition. At design condition, the maximum amplitude of pressure fluctuations happened on the blade leading edge, nearly 14% of average pressure, which was respectively 86% and 169% higher than the centers of the blade pressure side and suction side.