Optimization of Fan Noise by Coupling 3D Inverse Design and Automatic Optimizer

B1 - Computational Aeroacoustics

A methodology for designing fans to meet multi-objective design criteria is presented. The method combines a 3D inviscid inverse design method with a multi-objective genetic algorithm to design fans which meet various aerodynamic aero-acoustics and geometrical requirements. The parameterization of the blade shape through the blade loading enables 3D optimization with very few design parameters. A generic fan stage is used to demonstrate the proposed methodology. The main design objectives are improving profile losses to improve design point efficiency and reduce diffusion for better stall performance. The optimization is performed subject to certain constraints on Euler head, throat area, thickness and meridional shape so that the resulting fan stage can meet both design and off-design conditions. A Pareto Front is generated for the two objective functions and 3 different configurations on the Pareto front are selected for detailed study by 3D RANS code. The CFD results confirm the main outcomes of the optimization process.