12th European Conference on Turbomachinery Fluid dynamics & Thermodynamics
A novel design method for impellers of centrifugal fans with backward curved blades is proposed. The overall geometry of the impellers considered is kept close to customary industrial designs (e.g. circular arc blades). The design method is based on seven simple correlations which determine the geometrical impeller parameters as a function of the targeted aerodynamic duty (design) point. Unlike classic design methods, these correlations are derived from aerodynamic optimization. The objective function of the optimization is the maximization of total-to-static efficiency while precisely matching the targeted design points. The range of design points studied covers the full typical realm of centrifugal fans according to Cordier's diagram. A comparison to the classic slip theory as e.g. by Pfleiderer reveals that the novel method is superior regarding both fulfillment of the targeted design point and energy efficient performance.