Research on aerodynamic noise of the high-speed transportation based on experiment and simulation

By means of the switch inside the numerical model, the small-scale pulsation on the near wall is simulated by URANS method. Areas away from the wall are adjusted to the sub grid scale (SGS) models automatically, which is simulated for the vortex movement by LES method. Via the automatically adjustable method in accordance with local grids, not only the advantage concerning the small computation amount of URANS method can be shown in the boundary layer, but also the large-scale vortex movement can be simulated in the areas away from the wall. Firstly, based on the mentioned method, aerodynamic characteristics of the high-speed transportation in the near field are calculated numerically. As shown from the corresponding result, due to the sudden structural changes of nose tip and bogies, their surface pressures are larger. Therefore, the numerical optimization of the aerodynamic characteristics for the high-speed transportation can be conducted from this aspect. Secondly, based on the results of aerodynamic characteristics, the near-field and far-field aerodynamic noises of the high-speed transportation are also calculated. The near-field radiation noise is larger near the noise tip and bogies, while the far-field noise is greater near the ground. Finally, the calculation results of the near-field and far-field for the high-speed transportation are verified by experiments, and they are consistent with each other. As a result, the numerical model established in the paper is reliable.