带分流叶片高速离心泵的压力脉动分析及试验

An Analysis of Pressure Fluctuation of High-speed Centrifugal Pumps

采用Ansys-CFX软件对带分流叶片和不带分流叶片高速离心泵进行非定常数值模拟计算,分析了分流叶片在各个工况下对压力脉动特性的影响,并通过试验验证了数值模拟计算对高速离心泵外特性曲线预测的准确性.结果表明:带有分流叶片的高速泵比不带分流叶片的扬程略高一些,且随着流量的增加,扬程提高逐渐增大;带有分流叶片的高速离心泵出口处压力脉动出现了与分流叶片相对应的小峰值,在一定程度上有助于缓解高速泵出口压力脉动的急剧波动。在频谱图中,高速泵在其叶频处存在较大的峰值,说明叶频是其出口压力脉动的主要成分,即出口压力脉动是由于叶轮与蜗壳动静干扰引起的;在不同工况下,分流叶片对高速泵蜗壳内部和出口压力脉动也有良好的改善作用,即减弱动静干涉作用。

Ansys-CFX software is adopted to simulate the unsteady flow field under different operating conditions in a high-speed centrifugal pump whose impeller is designed with and without splitter blades. The influence of splitter blades on fluctuation is analyzed and a comparison of the results between numerical simulation and experiment is satisfactory. The results show that the rising ratio of the head was found increasing with the increasing flow rates. Moreover, the low peak of pressure fluctuation corresponding to the short blade of splitter blades has been found, which shows some degree of alleviating actions on the drastic changes of pressure fluc- tuation in the high-speed pumps by using splitter blades. Seen from the frequency spectrogram of the high-speed pump, the high peak lies at its bladeff passing frequency, which shows that the dominant frequency in the pump outlet is the blades＂ passing frequen- cy, mainly caused by the rotor-stator interactioru Under different operating conditions, the splitter blades can improve the pressure fluctuation in the internal face and the outlet of the pump.