离心泵内部非定常压力场的数值研究

为研究离心泵内部压力随叶轮旋转的变化，采用FLUENT提供的滑移网格技术对设计工况下离心泵内的非定常流动进行了数值计算，分析了离心泵内部非定常流动的规律。结果表明：离心泵内部流动的非对称特性和非定常特性明显；离心泵出口和叶片进口压力的波动对离心泵性能影响较大；在蜗壳中部截面S2和蜗壳出口截面S3上，静压的波动主要受叶片和蜗舌相对位置的影响，而动压的波动主要受叶片和截面相对位置的影响；两截面上沿蜗壳径向静压增大，动压减小；沿蜗壳周向静压随圆周角的增大而增大，而动压略成下降趋势。该分析为研究离心泵内流现象，降低离心泵的汽蚀、振动和噪声提供了有益的借鉴。

Numerical simulation of unsteady pressure field in centrifugal pumps

An unsteady numerical analysis of the entire field is conducted under the design condition for centrifugal pumps with the sliding mesh technology using FLUENT, and the unsteady flow characteristics in the pump were investigated for studying the variation of pressure with the rotating impeller. The results showed that the asymmetrical and unsteady characteristics were obvious. The fluctuation of pressure on the outlet of the centrifugal pump and the inlet of blade had great influence on the performance of the centrifugal pump. On volute middle section S2 and volute outlet section S3, the fluctuation of static pressure was influenced by the relative position of blade and volute tongue, and the fluctuation of dynamic pressure was influenced by the relative position of blade and corresponding section. With the increase of volute radius, the static pressure increased and the dynamic pressure decreased. Along the circumferential direction, with the increase of angle of circumference, the static pressure increases and the dynamic pressure decreased slightly. The results were given as beneficial reference for the research of the internal flow and the reduction of cavitation, vibration and noise of centrifugal pumps.