叶片包角对高比转速离心泵固液两相非定常特性的影响

Effect of Blade Packet Angle on Unsteady Characteristics of Solid-Liquid Two-Phase Flow of Centrifugal Pump with High Specific Speed

为了分析叶片包角在固液两相流下对高比转速离心泵非定常特性的影响,采用ANSYS CFX软件和Mixture多相流模型对5种不同叶片包角离心泵的固液两相流进行了非定常数值模拟,分析了叶片包角对固液两相流离心泵瞬时扬程、压力脉动及径向力的影响。研究表明:随着叶片包角每增大10°,固液两相流离心泵的瞬时扬程有所降低,波动时间会延迟0.001 s;流道内及隔舌处的压力值越来越小,脉动幅值越来越大,压力波动时间向后延迟0.001 s;叶轮上的径向力会增大,隔舌处的径向力会减小,受力方均向顺时针偏转;不同包角下的固液两相流离心泵叶轮流道内的压力脉动主频均出现在转频处,隔舌处的压力脉动主频出现在叶频处。其中,叶片包角φ=120°是叶轮流道内压力值和压力脉动幅值增减速度快慢的分界点,也是隔舌处的压力脉动幅值最小值点。

In order to explore the influence of blade wrap angle on the unsteady characteristics of high specific speed centrifugal pump under solid-liquid two-phase flow,the solid-liquid two-phase turbulent flow of five different vane angle centrifugal pumps is simulated by using the Mixture multiphase flow model and ANSYS CFX software.The non-constant constant value simulation is used to analyze the influence of blade wrap angle on the instantaneous head,pressure pulsation and radial force of solid-liquid two-phase centrifugal pump.The study shows that with the increase of the wrap angle of the blade(for every 10°),the instantaneous head of the solid-liquid two-phase centrifugal pump is reduced,and the fluctuation time is delayed by 0.001 s.The pressure in the flow channel and the tongue is decreased,while the pulsation amplitude becomes larger,and the pressure fluctuation time is delayed by 0.001 s.The radial force on the impeller will increase,the radial force at the tongue will decrease,and the force will be deflected clockwise.The main frequency of pressure pulsation in the impeller flow path of the solid-liquid two-phase centrifugal pump under different wrap angles appears at the frequency shift point,and the main frequency of the pressure pulsation at the tongue appears at the blade frequency.Among them,the blade wrap angle φ=120° is the demarcation point of the pressure value in the impeller flow channel and the transition point of the pressure pulsation amplitude.It is also the minimum value of the pressure pulsation amplitude at the tongue.