离心泵内部非定常流动易诱发压力脉动,进而导致泵体振动与流动诱导噪声问题,本文应用计算流体力学方法,研究蜗壳基圆直径变化产生的径向间隙对离心泵非定常流场及流动噪声的影响规律。研究表明：非定常流动下离心泵压力脉动主频均为叶频(290Hz),当基圆直径从1.01D?增加到1.06D?,蜗壳外圈测点a8处叶频下的压力脉动强度减弱了约20%,而叶轮上的压力脉动及所受激励力受基圆直径变化影响较小。在流动诱导噪声方面,基圆直径增加时,主频(290Hz)下隔舌处测点的振动加速度幅值从29.25m/s2降至约25.32m/s2,泵壳外壁上监测点1的总声压级从88.28dB降至87.09dB,但基圆直径的改变对离心泵外声场辐射指向性影响较小。

The unsteady flow inside a centrifugal pump can easily induce pressure pulsations, leading to pump vibration and flow-induced noise problems. In this study, computational fluid dynamics (CFD) methods are employed to investigate the influence of radial gap variations, caused by changes in the volute base circle diameter, on the unsteady flow field and flow-induced noise characteristics of the centrifugal pump. The results show that under unsteady flow conditions, the dominant frequency of pressure pulsations corresponds to the blade passing frequency (290 Hz). When the base circle diameter increases from 1.01D? to 1.06D?, the pressure pulsation intensity at the blade passing frequency at monitoring point a8 on the volute outer wall decreases by approximately 20%, while the pressure pulsations and excitation forces acting on the impeller are only slightly affected by the base circle diameter variation. Regarding flow-induced noise, as the base circle diameter increases, the vibration acceleration amplitude at the tongue at the dominant frequency (290 Hz) decreases from 29.25 m/s2 to approximately 25.32 m/s2, and the overall sound pressure level at monitoring point 1 on the pump casing decreases from 88.28 dB to 87.09 dB. However, the variation in the base circle diameter has little impact on the radiation directivity of the external sound field.

TK263

国家自然科学基金项目,国家自然科学基金项目（面上项目，重点项目，重大项目）