Design optimization of a low-speed fan blade with sweep and lean

Abstract The present work performs numerical optimization for design of blade stacking line for an axial flow fan with response surface method using three-dimensional Navier—Stokes analysis, and evaluates the effects of sweep and lean on the performance of the fan blade. Reynolds-averaged Navier—Stokes equations are discretized with finite-volume approximations using unstructured grids. Four geometric variables concerning spanwise distributions of sweep and lean of blade stacking line are chosen as design variables to find maximum efficiency. The computational results show good agreements with experimental data. The total efficiency is successfully increased in comparison with the reference fan by optimizing three-dimensional stacking line with sweep and lean. Coupling of sweep and lean also improves off-design performance of the blade remarkably.