Coefficient-enlargement method for design of low specific-speed centrifugal pump

On the basis of traditional formula for the outlet width of impeller and specific-speed,the formula with enlarged coefficients of the flow-rate,head and specific-speed was derived,which incarnates the relation of enlarged coefficients to the hydraulic parameters of the pump.The calculation method with enlarged coefficients for centrifugal pump based on performance prediction of centrifugal pump was proposed.The problem of pump design being unable to make sure that its efficiency is the highest when they decide the enlarged coefficients only according to experience statistics was solved.The example indicated that the method proposed here is practicable,which can enhance the efficiency of low-specific speed pump at design condition.The design theory of low specific-speed centrifugal pump was further enriched.