Abstract: Taking a single-stage end-suction centrifugal pump as study object and assuring the inlet and outlet setting angle and diameter and as well as other parameters unchanged, five sets of pump models with different outlet width of impeller were designed respectively, their numerical simulation was carried out one after another and the influence of impeller outlet width on the performance and pressure fluctuation was analyzed. It was shown by the study result that with the increase of impeller outlet width, the lift and shaft power would increase to different extent, the efficiency curve would be hump shaped, indicating that there would be an optimum impeller outlet width to make the flow loss minimum; increasing the width of the impeller outlet, flow separation phenomenon in flow channel would be enhanced, blocking phenomenon there would decrease hydraulic loss would decrease thereby, indicating that an appropriate width of impeller outlet would be effective for reducing the energy loss of centrifugal pump. With progressive decrease of impeller outlet width, the shaft frequency peak would change obviously, assuming progressive increase trend, indicating that an excessive narrow impeller outlet width would easily lead to flow blocking in flow passage and hinder the development of the flow mode, At the same time, the impeller outlet width would also have a greater effect on pressure pulsation in centrifugal pump.

Key words: centrifugal pump, impeller exit width, pressure fluctuation, numerical simulation