Design program for axial flow impeller blade based on Joukowski transform
To improve the performance of axial flow pumps and upgrade the design principle of the pump blades, a new approach for calculating the blade camber was proposed here. The principle and procedure that the approach designs the blades of axial flow impeller were presented based on the Joukowski transform. The geometrical properties of an eccentric circular cylinder, which was formed by the superposition of three two-dimensional potential flows—a doublet, a uniform plane flow and a point vortex, fluid dynamics around it and the position of stagnation point on it were described. Further, the geometrical properties of a circle arc, which was derived from Joukowski transform, and the fluid dynamics around it were discussed as well. Based on the above achievements, the method and producer for determining the direction and shape of a blade camber were developed in terms of the specified circulation and freestream velocity. The method and producer proposed here are completely different from the traditional ones, such as the singularity method, streamline method and so on for axial flow pump blades. The new approach is easily handled by pump engineers and it is hopeful that the approach can offer a new way for designing axial flow pump blades for the engineers.