多翼离心风机旋转失速阶段压力脉动分析

Pressure pulsation analysis during rotational stall stage of multi-wing centrifugal fan

为了研究多翼离心风机在旋转失速阶段的压力脉动特性,以多翼离心风机为研究对象,利用Creo软件对其进行三维建模,并对模型进行网格划分,进行非定常数值计算.在叶轮出口不同周向、径向以及轴向位置设置监测点,分析旋转失速工况下风机内部压力脉动规律,计算结果表明:隔舌处监测点的压力系数最大,且随着流量的减小,压力脉动剧烈程度增大;叶轮出口受叶轮与蜗壳之间动静干涉影响,压力系数幅值最大,往蜗壳壁面径向移动,压力脉动程度减弱;压力脉动规律受轴向位置变化影响较小,旋转失速程度的变化会引起压力脉动的变化,旋转失速越强,压力脉动越剧烈,低频脉动范围越广,失速频率幅值越高.

To investigate the pressure pulsation characteristics of multi-wing centrifugal fans in the rotational stall stage,taking the multi-wing centrifugal fans as research object,the Creo software was used to model in three dimensions,and the models were meshed and calculated for unsteady values.Monitoring points were set in different circumferential,radial and axial positions of the impeller outlet,and the internal pressure pulsation law of the fan under the rotational stall condition was analyzed.The calculation results show that the pressure coefficient of the monitoring point at the diaphragm tongue is the largest,and with the decreasing of flow,the intensity of pressure pulsation is increased.The impeller outlet is affected by the dynamic and static interference between impeller and volute,and the amplitude of the pressure coefficient is the largest.When it moves radially to the volute wall,the pressure pulsation degree is weakened.The law of pressure pulsation is slightly affected by the axial position change,while the change of rotational stall degree can cause the change of pressure pulsation.The stronger the rotational stall is,the more intense the pressure pulsation is.The wider the low-frequency pulsation range is,the higher the stall frequency amplitude is.