The Study On The Measurement Of Flow Fields In A Pump Sump By Three-Dimensional Particle Image Velocimetry

A pump sump is a transition segment which connects a forebay and the intake of a pump, the aim of which supplies the good flow condition for the intake of the pump and satisfy the conditions of the hydraulic design of the pump.In the ordinary way, the model-test method is applied to improve the flow condition in the pump sump. In the late years, with the development of the technique of the numerical calculation and the computer image, the research methods are more and more diversififul.This dissertation aimed at the key question of the research for the pump sump, i.e., the precise mesurement of the folwfields.The auther adopted virginly the technique of the 3DPIV at home, and acquired the reliable measurement data, which assumes the important realistic signification for revealing the essence of the flowing in the pump sump, verifying the mathematical model of the CFD computation and boundary conditions, and optimizing the hydraulic design of the pump sump.The author designed and mounted independently an experimental equipment that is adapt to the measurement of the 3DPIV. The diameter of the impeller of axial-flow pump is 150mm, the shape of the opening pump sump which is made of diaphanous organic glass is rectangle. Firstly, the performance of the pump was measured at the operating speed of 1450rpm. Secondly, the 3DPIV was applied to the measurement of the flow fields under the bell of the pump in the opening sump after solving the calibrations of the measurement sections in the pump sump. Thirdly, three whole flow fields were obtained from three difference perspectives by the postprocessing of the measurement data, and the character of the flow fields in the measurement sections was acquired. Furthermore, the measurement flow fields were compared with the existing results from the experiments and numerical calculation. At last, the sources that the errors produced in the measurement course were discussed and the methods to reduce errors were also put forward.According to the verification of the experiment results, the technique of the 3DPIV is completely adapt to the measurement of the flow fileds in the pump sump,and the actual condition of the three-dimensional flows in the measurement sections was obtained correctly, which is more helpful for the proof of the results of the numerical calculation, the optimization of the hydraulic design of the pump sump, and the high-performance operation of the pump.