Optimization of axial fans with highly swept blades with respect to losses and noise reduction

A low pressure axial fan with swept blades is optimized with respect to sound emission and efficiency. Noise is addressed by a modified sweep strategy. Regarding aerodynamics, geometrical parameters describing variations of the blade section and the hub contour are defined. The optimum in terms of maximal total-to-total fan efficiency at the design point is achieved by numerous CFD simulations embedded in the Simplex optimization method. Besides a moderate increase in efficiency at the design point, a remarkable extension of operating range is observed. The numerical results are successfully validated against experiment measurements. Acoustic measurements furthermore show a decrease in sound emission over the complete operating range. (C) 2012 Institute of Noise Control Engineering.