NUMERICAL ANALYSIS OF AERODYNAMIC NOISE RADIATION FROM A HIGH-SPEED TRAIN SURFACE

The aerodynamic noise radiation from a vestibule side door on a high-speed train surface is calculated by the combination of unsteady incompressible fluid flow analysis and acoustic analysis. Pressure fluctuation on a vestibule side door surface is measured to verify the results of fluid flow analysis. Analysis results agree with measured data very well at low frequencies. For high-frequency components, the solvable frequency is limited by the analysis mesh size. Required mesh size is typically one eighth of the wavelength of the pressure fluctuation on the model surface. The aerodynamic noise is mainly radiated from around the following corner where the vortices that are shed from the leading corner strongly interact with the train surface.