A new approach is provided for blade design on stream surface of revolution based on a novel image plane theory of cascade blading.A flow solver in differential integral formulation for analyzing the flow field of a given geometry is transformed into a design method by coupling with a contour modification model.In this method the classical slip condition is replaced by other boundary conditions.In such a way the prescribed velocity or pressure distribution can be imposed directly on the blade.Since the blade shape is compatible with the velocity requirement

a nonzero velocity component normal to the blade wall evolves from the flow calculation.This normal velocity is then used to reset the wall parallel to the new flow field

using a transpiration technique.The procedure is repeated until the calculated velocity distribution converged to the required one.Numerical results of an actual turbine nozzle show that the present method can provide a practical blade without strict requirement for its initial shape.Another important aspect of this method is the ability to design and analyze a blade with identical code.