This paper presents an aerodynamic design method for half-ducted axial flow fan using meridional viscous flow analysis and one-dimensional inverse method. The meridional viscous flow analysis which can take into account the mixing loss related to the vortices in the meridional flow field. A conventional half-ducted axial flow fan has been investigated by a three-dimensional Reynolds Averaged Navier Stokes analysis (3D-RANS) and the meridional viscous flow analysis. The 3D-RANS analysis result shows a flow separation on the suction surface near the trailing edge of the blade. In addition, the meridional viscous flow analysis results shows the high blade loadings near the trailing edge of the blade. The blade shape has been redesigned by the present design method with improved blade loading distributions which has lower blade loading near the trailing edge. The numerical result shows the flow separation is successfully suppressed as intended in the design concept. As a result, the aerodynamic performance in the designed blade is improved.
