Numerical simulation of dynamic flow characteristics in a centrifugal water pump with three-vaned diffuser

Zhi-Jun Shuai,Zeng-Hao Zhou,Chen-Xing Jiang,Feng-Chen Li,Dong-Hua Wang

doi:10.1177/1687814015598487

Abstract

The complex three-dimensional turbulent flow field in a centrifugal water pump with three asymmetrical diffusers was numerically simulated. The characteristics of pressure and force fluctuations inside the model pump were investigated. Fast Fourier transformation was performed to obtain the spectra of pressure and force fluctuations. It indicates that the dominant frequency of pressure fluctuations is the blade passing frequency in all the sub-domains inside the pump and the first blade passing frequency energy (first order of blade passing frequency) is the most significant. The dominant frequency of pressure fluctuations at the location of diffuser outlet is featured by low frequency (less than 1 Hz), which may be due to the locally generated eddy structures. Besides, the dominant frequency force fluctuations on the impeller blades are also the blade passing frequency. The existence of the three asymmetrical diffusers has damping effect on the pressure fluctuation amplitude and energy amplitude of pressure fluctuations in the diffuser domain dramatically, which indicates that the diffusers can effectively control the hydraulically excited vibration in the pump. Besides, the prediction of the dominant frequency of pressure fluctuations inside the pump can help to utilize the pump effectively and to extend the pump life. The main findings of this work can provide prediction of the pump performance and information for further optimal design of centrifugal pumps as well.

Highlights

The centrifugal water pumps, a kind of widely used fluid machinery, play an important role in almost all industrial and agricultural fields
From the results shown above, we can see that the performed numerical simulation can accurately predict the total water head of the model pump with a deviation of about 2% compared with the experimental result (Figure 3); the behaviors in the flow field under steady state inside the centrifugal pump are all reasonable, which demonstrates that the numerical procedure in our study is reliable
The characteristics of the rotating turbulent flow in a centrifugal water pump with three asymmetrical diffusers have been studied through computational fluid dynamics (CFD) numerical simulations

Summary

Introduction

The centrifugal water pumps, a kind of widely used fluid machinery, play an important role in almost all industrial and agricultural fields. From the results shown above, we can see that the performed numerical simulation can accurately predict the total water head of the model pump with a deviation of about 2% compared with the experimental result (Figure 3); the behaviors in the flow field under steady state inside the centrifugal pump are all reasonable, which demonstrates that the numerical procedure in our study is reliable.

Results

Conclusion