Investigation of Flow-Induced Noise Characteristics in the Oblique Flow Pump

Abstract

An oblique flow pump is widely used in farmland irrigation and drainage, water transfer projects, thermal power generation, and other fields. However, unstable flow factors in the oblique flow pump easily lead to pump vibration and noise. To improve the stability of pump operation and optimize the operating environment, it is necessary to study the flow-induced noise characteristics of oblique flow pumps. In this paper, CFD and noise simulation software are used to calculate the flow field and sound field of the oblique flow pump. The internal flow characteristics and flow-induced noise characteristics of the oblique flow pump were studied. The results show that when the flow rate of the oblique flow pump deviates from the optimal operating point, especially in the small flow rate, due to the phenomena of backflow and flow separation, more high-energy vortices are produced in the flow channel, and the vortices are distributed in a wide area, which will cause greater flow-induced noise. It is found that with the increase in flow rate, the sound pressure level of flow noise in the inlet channel gradually decreases, the sound pressure level in the guide vane region first decreases and then increases, and the sound pressure level is the lowest at 1.0Q. Generally speaking, the noise sound pressure level in the outlet channel region of the pump also gradually decreases. In addition, at the blade frequency, the radiated noise of the oblique flow pump can show dipole characteristics under various flow conditions, and the radiation level of sound pressure increases with the increase in flow rate. This paper can provide a theoretical basis for the mechanism research and control strategy of flow-induced noise in oblique flow pumps.