The Study Of Aerodynamic Effect On High Speed Train Bottom Plates

ABSTRACT:The cabin of high speed train is an elongated box-type structure, large equipment are installed inside the cabin, the surface is coverd by apron board and bottom plate, the damage of the structure is a major security risks to high-speed train. With the increasing of running speed, and passenger special lines have intensive tunnels, the ground aerodynamic effect has become more evident. It is necessary to study on the aerodynamic effect of the bottom plate. In view of the flutter has the strong ability of destruction, leading to some undesired vibration, and causing fatigue problem. So just like the design of aircraft, the bottom plates of high-speed train need to exclude flutter in the range of sound velocity.This paper is based on the theory of the steady potential flow, to establish the motion equation of the board under aerodynamic loads. Respectively Ritz-Galerkin method, and differential quadrature method to discrete motion equations, to solve the equations by programming, to determine the stability of the structure. Finally, using the Newmark method to get the time domain response of the board, and getting the displacement response and the frequency response when the board is instability.According to the theory of fluid-solid coupling and by using the ANSYS/CFX method to establish the fluid-solid coupling model of three-dimensional panel to calculate the instability velocity of it and obtain the displacement and pressure responses of the panel under different speed of the incoming flow, then Compare with the theoretical calculation results to verify the applicability of the ANSYS/CFX method.Researching the aerodynamic effect of the ground surface (the feather of the aerodynamic loading) at the basis of the test data which root in the CRH380AM running between Shanghai-Kunming high speed railway. And studying the pressure deviation rule of the bottom plate under different speed levels and different working conditions(across the series of tunnels). Proceeding the transient dynamics analysis of bottom plate under the measured aerodynamic loads, to gain the strain response and displacement response. Judging the aerodynamic stability, and analysis the relationship between the stress and aerodynamic load by displacement responses.Through the study of this paper, it provides a way of aerodynamic characteristic analyzing of the high-speed train bottom plate. Besides, it means a lot for the design of the structure of bottom plate.