Influence of Rotation Speed on Flow Field and Hydraulic Noise in the Conduit of a Vertical Axial-Flow Pump under Low Flow Rate Condition

The complex flow inside the axial-flow pump device will cause problem of hydraulic noise; in order to explore influence law rotation speed on internal characteristics and noise conduit, a combination Computational Fluid Dynamics (CFD) Acoustics (CA) was used numerically solve field sound device. results showed that elbow inlet conduit smooth at different speeds, there no obvious unstable flow. higher speed, more disordered pattern left half elbow, which intensifies straight outlet conduit. impeller is main source hydrodynamic vertical When propagates upstream downstream along Total Sound Source Intensity (TSSI) gradually decays with increase distance; greater is, faster decays. increased from 1450 r/min 2200 r/min, TSSI attenuated by 8.9 dB, 13.9 16.0 dB respectively, 11.0 13.5 25.9 respectively. vortex structure induces delays attenuation propagation process; this delay be obvious.