The Experimental Study On The Flow Fields In An Unshrouded Centrifugal Pump Impeller By PIV

In recent decade years, with the development of the flow measurements ,the PIV is accepted and applied as the fundamental measurements for the flow fields by the researchers.The author designed an unshrouded centrifugal impeller, set in the transparent centrifugal pump. The velocity-coefficient method was used to design a 180mm diameter impeller with five single-arc-cylinder blades. The exit angle and inlet angle of the segment are 35.1 and 36.0 in degrees respectively. The shape volute's cross-section is the rectangle. The inlet of the pump and the axis are in the same side. Although the structure of the pump is different from the normal one, the performance of the pump can be measured and the internal flow fields in the volute and impellers can be investigated by using PIV easily.The performance curve was acquired at the pump operating speed of 1200rpm.PIV was applied to the measurements of the flow fields in the unshrouded centrifugal pump. During the measurements , three operation points of the pump were taken. The ratios of the flow rate (Q/Q) are 1.4 1.0 0.6 respectively. Three blade-to-blade passage and the three cross-section along the axial direction at each of the passages were selected for measurements. The absolute velocity was decomposed based on the law of velocity triangle, the absolute tangential velocity, the relative velocity and the relative tangential velocity were presented in this paper. The measurements flow fields were compared with the existing one from the experiments and numerical computation.This thesis was supported by the projects of the Study on PIV Measurements of The Flow Fields Inside the Pump Impeller sponsored by the State Nature Science Fundof China.