Improvement and validation of a planar cascade inverse design method

With the hypothesis that one fluid element moves along a curved average streamline in cascade passage due to the pressure force acting on the element, a feasible planar cascade inverse design method was introduced; the design parameters for yielding desired cascade geometry mainly include: inlet/outlet flow angles, section radius, prescribed profile loading and thickness distribution along axial chord. To supplement and improve original design method, a new theory was put forward, in which the density distribution along axial chord could be calculated, and the algorithm with leading/trailing circles was modified with obvious improvement of cascade aerodynamic performance. To validate the improved cascade design method, the Aachen turbine cascade from Germany was re-designed in this paper.