时序效应对导叶式离心泵水力特性与流致噪声的影响

Influence of Clocking Effect on Hydraulic Characteristics and Flow Noise of the Centrifugal Pump with Vaned Diffuser

为研究导叶相对蜗壳隔舌的时序效应对导叶式离心泵水力特性及流致噪声的影响,以某型号导叶式离心泵为研究对象,通过试验验证数值模拟的可靠性,分析设计工况下导叶不同时序位置(CL)时离心泵的水力特性和声场特性。结果表明:随着CL增大,泵的扬程时均系数、效率时均系数和总声压级系数均呈现先增大后减小的高斯分布规律。CL=0.267为导叶相对最优时序位置,此时泵的扬程和效率达到相对较高,而噪声处于相对较低水平。时序效应对泵内蜗壳隔舌附近流体流动造成影响,导致泵水力性能的改变。在泵的流致噪声中,叶轮诱导噪声为泵噪声主要来源,其声压级值高于其他部件诱导噪声。泵中各部件的压力脉动与声压级在频域上均呈现明显的离散特性,在叶轮叶频及倍频处出现峰值。研究结果为离心泵中径向导叶相对位置的确定提供参考依据。

In order to study the influence of clocking effect with the guide vane relative to volute tongue on the hydraulic characteristics and flow noise of guide vane centrifugal pump,a certain type of diffuser centrifugal pump was taken as the research object.The reliability of numerical simulation was verified by experiment,and the flow field characteristics and sound field characteristics of the centrifugal pump were analyzed at different clocking positions under the designed condition.The results show that with the increase of CL,the head time-average coefficient,the efficiency time-average coefficient and the total sound pressure level coefficient of the pump show the gaussian distribution pattern of firstly increasing and then decreasing.CL=0.267 is the relatively optimal clocking position of the guide vane,at this time,the headand efficiency of the pump are relatively high,while the noise is relatively low.The clocking effect affects the fluid flow around the volute tongue in the pump,resulting in the change of the hydraulic performance of the pump.In the flow noise of the pump,impeller-induced noise is the main source,and its sound pressure value is higher than that of other components.The pressure pulsation and sound pressure level of each components in the pump show obvious discrete characteristics in the frequency domain,and the peak occurs at the frequency and frequency doubling of the impeller blade.The results could provide a reference for the relative position determination of radial guide vane in centrifugal pump.