Effects of the outlet position of splitter blade on the flow characteristics in low-specific-speed centrifugal pump

Jinfeng Zhang,Guidong Li,Yefei Qu,Jieyun Mao,Shouqi Yuan,Jing Jia

doi:10.1177/1687814018789525

Abstract

To elucidate the influences of the outlet position of splitter blades on the performance of a low-specific-speed centrifugal pump, two different splitter blade schemes were proposed: one located in the middle of the channel and the other having a deviation angle at the trailing edge of splitter blade toward the suction side of the main blade. Experiments on the model pump with different splitter blade schemes were conducted, and numerical simulations on internal flow characteristics in the impellers were studied by means of the shear stress transport k- ω turbulence model. The results suggest that there is a good agreement between the experimental and numerical results. The splitter blade schemes can effectively optimize the structure of the jet-wake pattern and improve the internal flow states in the impeller channel. In addition, the secondary flow and inlet circulation on the pressure surface of main blade, the flow separation on the suction side of splitter blade, the pressure coefficient distributions on blade surface can achieve an evident amelioration when the trailing edge of splitter blade toward the suction side of the main blade is mounted at an appropriate position.

Highlights

The low-specific-speed centrifugal pump has the advantage of high head and compact structure
The head increases by 5.16% and 13.2% and the efficiency increases by 0.8% and 9% at flow rate 3.15 kg/s in scheme 1 and scheme 2, respectively
The contours of radial component of relative velocity for three schemes at the impeller outlet are shown in Figure 8, which is normalized by impeller outlet circumference velocity U2

Summary

Introduction

The low-specific-speed centrifugal pump has the advantage of high head and compact structure. In order to analyze and verify this influence of the outlet position of splitter blade on the internal flow characteristics and pump performance in the low-specificspeed centrifugal pump, combined experimental tests and numerical calculations were utilized to analyze the main reasons affecting the performance of the pump at the best efficiency point flow rate. In the case of prototype propeller (Figure 10(a)), the streamline deviates from the blade shape seriously in the mid part of PS, which is the main region that affects the flow field and pump performance.

Results

Conclusion