The polar angle of a variable point defining the trajectory of a fluid particle in a centrifugal impeller is obtained using mechanics of particles in a rotating coordinate system. The expression for the angle then yielded the impeller outlet relative flow angle, which was used to calculate slip factor. An attempt to explain the phenomenon of slip using an oblique coordinate system with axes in the direction of the tangent to a vane and in the tangential direction then enabled a new expression for slip factor to be obtained. The computed values of slip factor using available pump data compare reasonably well with reference values.
