Anti-method. Axial Flow Turbomachinery Blade Optimization Design Study

Axial blade machines are generally used in civil and military products, and the higher blade-designing technology is the key to the further development of the blade machines.The design method proposed in this paper is, in principle, based on the potential-stream function inverse method, using numerical optimization to obtain optimized blade profiles. As we know, inverse techniques make blade's profile well compatible with its surface velocity distribution, however, they give designers big challenges that the ideal velocity distribution is hard to obtained and sometimes the non-physical solution, such as double covering of flow field or unclosed profiles, would come out. The proposed design procedure in the paper has avoided the disadvantage mentioned above.In this paper, a quasi-irrotational equation is used to describe the flow in cascade instead of the generally used irrotational equation. Then a Laplace equation can be deduced and through computation, the blade profile coordinates and geometry of the cascade result from an analytical solution. Next, an optimization method, taking the geometry parameters of the unclosed profile as its objective functions, is used to obtain an optimized blade profile. And last, the optimized profile is refined with round arcs added in the leading and trailing edges. Several axial turbine and compressor geometry profile designs are presented. Also some turbine and compressor sample cascade design cases and their calculated performance for different prescribed conditions are given and discussed. In the design procedure, the presented method in the paper shows its applicability and effectiveness, especially for modification of the proscribed velocity distribution.