Optimization Design for Aerodynamic Noise Reduction of Train Air-Conditioning Axial Fan

Abstract

This paper introduces an axial flow fan used in a train air-conditioning condensing system, which is the main sound source of the system. Firstly, in order to analyze the main causes of aerodynamic sound, the wind tunnel model of the axial flow fan for Computational fluid dynamics (CFD) analysis was established. The accuracy of the wind tunnel model was verified by axial fan P-Q performance curve and static pressure efficiency curve obtained from the test. Then the causes of aerodynamic sound of the axial flow fan was investigated by CFD analysis using the Large Eddy Simulation (LES) turbulence model and the Ffowcs Williams-Hawkings model (FW-H). Finally, three different optimization schemes of axial flow fan were proposed and compared with the prototype fan. The result shows that the pressure gradient at blade tip can be reduced by modifying blade airfoil and increasing chord length, and the aerodynamic noise of axial flow fan can be improved, which proves that the noise reduction scheme is effective.