Quasi-Three Dimensional Design Of Diagonal Flow Fan Impeller And Numerical Analysis

The diagonal flow fan has both the advantages of axial flow type and that of centrifugal type, the former of which is large coefficient of mass flow, high efficiency, and the latter is large pressure coefficient, wide span of work condition. Consequently the diagonal flow type is a perfect selection for the performance zone which both the axial flow type and the centrifugal type can't reach, ant it has great value for engineering application.In the thesis, the design method of the diagonal flow fan impeller has detailedly researched Different from the previous means borrowing and extending design methods for axial flow or centrifugal type, a complete design method has presented on the basis of Quasi-Three Dimensional Design idea. The course is mainly composed of such steps as meridional surface design, inverse problem computation in meridional surface, blade shaping on stream surface, and verifying through three dimensional computation, until the design requirement is met at last. The idea of the design method throws off the reliance on the engineering experience, avoids complicated special transformation, and has the blade profile and impeller optimized. According to the method, a set of computer program for inverse design has been made and the design result has been verified with code of 3-D analysts, on the basis of which design by direct-inverse problem iteration and optimization can be executed.It is indicated by the design example that the method in the thesis is feasible. The design impeller can meet the design requirements, and has steady total performance, reasonable parameter distribution, and less flow loss.