Research on the Reduction of the Aerodynamic Drag and Noise of EMU6 Air Conditioner

Abstract

With 1/8 th Scale of the Electric Multiple Units (EMU) 6 as model, the effects of air conditioner height and guiding angle on the aero-acoustic performance of EMU6 are studied, based on the 3D incompressible Lilly LES+FW-H method. The results show that the aerodynamic drag and noise of EMU6 are smaller when the air conditioner height is 190mm and the diversion angle is 30 degrees. The intensity of the dipole sound source near the air conditioner is larger. The A-weighted sound pressure level reaches the maximum at the frequency slightly lower than 1000Hz. The frequency band for the aerodynamic noise is wide, and the acoustic energy concentrates at the frequency around 1000Hz and decays with the increase and decrease of frequency. The sound pressure level is high at the streamline of the head coach and decreases gradually with the increase of distance from the tail coach.