A Study On Car Body Structure Noise Sensitivity Dynamic Aerodynamic Loads

Since the reform and opening up, China’s railway construction has been fully developed, especially in the last ten years in our country’s high-speed rail has been developed considerable development but at the same time, high-speed railway has also revealed a number of shortcomings. As more and more passengers choose to take high-speed rail travel, which is China’s high-speed rail technology put forward higher requirements, especially the noise problem. Research shows that when the train speed up to300km/h, the noise due to vibration caused by the body structure has become the main source of train noise.This article is based on "CRH3" as a geometric model, based on the corresponding three-dimensional modeling software model train aerodynamic flow field, and the use of air vehicle dynamics simulation software Fluent aerodynamic simulation analysis performed under different road conditions, the focus structural analysis of the air near the main side walls, roof, floors, windows and dynamics, then based disaster simulation (LES) numerical simulation methods to get the train surface200km/h and300km/h speed under fluctuating pressure. Then use acoustic analysis software Actran, carried on the body structure and Tune modal analysis, the phenomenon has been between20Hz and40Hz when resonance occurs. Then in the same manner using the acoustic analysis Actran aerodynamic loads extraction surface of the body, followed by an extraction is applied to the body surface of the aerodynamic load of the vehicle body as a boundary condition, and the frequency response of the vehicle to obtain the frequency response of the tune, also analysis of the frequency response of a single tune aerodynamic loads, get the greatest impact on the aerodynamic loads. Finally, based on the thickness of the main body structure as a design variable, the acoustic sensitivity of the compartment obtained six points, and to analyze the impact of the most important components, in addition to affecting the most important components for further analysis.