The Design of Axial Flow Pumps

A design procedure for axial-flow pump impellers is presented that accounts for induced interference effects in the prediction of performance. Induced interference velocities at an impeller blade have been calculated using a three-dimensional model that includes the effects of the other blades and of the total downstream vorticity along the center line of the pump. The design method considers improvement of cavitation conditions by specifying the radial variation of the design parameters such that the pressure distributions on all radial sections are similar. An analysis of optimizing the impeller geometric parameters for cavitation conditions is presented to permit the initial choices of the quantities appearing in the design procedure. Experimental work on a two-bladed impeller has yielded results that give good support to all aspects of the design method.