双蜗壳泵压力脉动特性及叶轮径向力数值模

为揭示双蜗壳离心泵的水力不稳定性,采用雷诺时均方法和SST k-ω湍流模型,对一双蜗壳双吸离心泵进行了三维非定常湍流数值模拟,得到了泵内部流场特性及双蜗壳内压力脉动情况.并对其进行了频谱分析.结果表明双蜗壳内存在比较明显的压力脉动.设计工况下压水室内的压力脉动强度小于非设计工况.在设计工况下,隔舌处和隔板区压力脉动频率均以叶片通过频率为主,其中隔板起始端的脉动幅值最大,约为隔舌处的2.5倍.在大流量工况下,隔舌处和隔板起始端压力脉动频率以叶片通过频率为主,而小流量工况下以叶轮转顿为主.叶轮受到的径向力随着叶轮的旋转呈现不稳定性,其中小流量工况时最明显.3种工况下径向力均指向隔板起始端侧.

Simulation of Pressure Fluctuation and Radial Force in a Double Volute Pump

The three-dimensional, unsteady Reynolds-averaged Navier-Stokes equations with shear stress transport turbulent (SST) models were solved to investigate the flow field and the characteristic of pressure fluctuations in the double volute. The results show that the pressure fluctuations are strong in the double volute. The pressure fluctuations in the volute are relatively low at the design flow rate condition. The blade passing frequency dominates the pressure fluctuations near the volute tongue and the clapboard at the design flow rate condition. The amplitude of the pressure fluctuation is largest at the beginning of clapboard, which is 2.5 times larger than at the volute tongue. At the large flow rate condition, the blade passing frequency is also dominative in the pressure fluctuations, but at the small flow rate condition the rotation frequency becomes dominative. The radial force on the impeller is unsteady especially at the small flow rate. At three flow rates, the radial forces all point at the beginning of clapboard.