带小叶片螺旋离心泵压力脉动特性分析

为了研究带小叶片的单叶片螺旋离心泵压力脉动特性,采用Navier-Stokes方程和标准的k-ε湍流模型对带小叶片和单叶片的螺旋离心泵的内部流场进行非定常数值计算。通过模拟分别获得了带小叶片和单叶片的螺旋离心泵蜗壳出口以及蜗壳内部压力脉动特性,并对其进行对比分析。结果表明:各个工况下,带小叶片和单叶片的螺旋离心泵蜗壳出口以及蜗壳内部压力脉动特性呈周期性变化,且主频均为各自叶片通过频率,压力波动的幅度大部分集中在低频区域;采用小叶片后周期变为原模型周期的一半,蜗壳及蜗壳内部出口压力波动的幅度明显减小,脉动幅值也明显减小,且高频脉动有所减少。研究表明单叶片螺旋离心泵叶轮小叶片的添加可以有效改善泵内部压力脉动特性,且对降低蜗壳上的振动噪声有一定积极作用。

Characteristic Analysis of Pressure Fluctuation of Unsteady Flow in Screw-type Centrifugal Pump with Small Blade

In order to research pressure fluctuation of unsteady flow in screw-type centrifugal pump with small blade,three-dimensional unsteady flow field of the pump was simulated numerically to the screw-type centrifugal pump with and without small blade based on Navier-Stokes equations and k-ε turbulent model.Pressure fluctuations in the outlet of pump and in the volute were obtained at different flow rates.The analysis results indicated that the pressure wave in the pump was always periodic in the two models,and impeller blade passing frequency was the dominant frequency.Compared with the result of single blade at different flow rates,the period decreased to half,and the amplitudes of pressure fluctuations in the pump was smaller,the high-frequency components were also fewer.The analysis results indicate that the adding of small blade in impeller of screw-type centrifugal pump with single blade can not only decrease the pressure fluctuation of unsteady flow in the pump,but also decrease oscillations in volute.