Multi-point airfoil optimization for axial-flow fan

Airfoil is the element of fan blade design.It is strongly anticipated to design a fan of averaged high performance over a wide operation range.Multi-point optimization design of airfoil for axial flow fan was proposed over specific operation range.Weighted objective function of airfoil lift-drag ratio was constructed for several operation points around the designing one.Airfoil was defined by parametric B-spline curve of limited shape controlling points.Results show that normal standard airfoils have remained spaces to be optimized under specific operation conditions.Airfoil performance is sensitive to flow's Reynolds number and cascade solidity.Predicting flow transition along airfoil profile is essential to search for optimized one.Optimized airfoil of wide operation range is possible to obtain with prescribed fitness function.Obtainments of multi-point optimization may be relatively lower at design point,but positive obtainments are achieved at off-design ones.Resulted airfoil is specially suitable for axial flow fans operating frequently at off-design point such as air condition coolers.