Recent Studies on Aerodynamic Noise Reduction at RTRI

Summary

As the maximum speed of high-speed trains increases, the effect of aerodynamic noise on the sound level at the wayside of the track becomes important. When the surface of bluff bodies such as pantographs is covered with porous materials, the aerodynamic noise generated by unsteady motion of vortices is significantly reduced. Experimental evaluation techniques of instantaneous flow fields using time-resolved PIV enable prediction of sound in the far field based on the theory of vortex sound. Aerodynamic noise emitted from a partial model of a pantograph is predicted numerically by coupling the calculation of unsteady flow with the evaluation of acoustical behaviour. The simulation succeeds in giving detailed information on the structure of aerodynamic sound sources.