Research On Flow Field,drag Reduction And Noise Reduction Of Pantograph Of High-Speed EMU

With the continuous improvement of the running speed of high-speed train,the proportion of aerodynamic resistance in the total resistance of the train increases significantly,including the aerodynamic resistance of pantograph,which restricts the further speed-up of high-speed train and affects the safe and stable operation of the train.Therefore,it is particularly important to improve the aerodynamic characteristics of pantograph.In this paper,the sss400+ pantograph combination model including a certain highspeed EMU is taken as the research object,and four pantograph combination models with different ripple positions are set up by adding corrugated structure on the windward side or leeward side of the carbon sliding plate of the pantograph head by using the method of combining numerical theoretical calculation,turbulent numerical simulation,relevant contact force standards and literature results.The aerodynamic lifting force of pantograph,the flow field characteristics of different pantograph combination models under cross wind,and the aerodynamic characteristics of pantograph under four operating conditions are numerically calculated and analyzed.It is proved that the optimized pantograph head carbon sliding plate has a good effect on reducing resistance and noise of pantograph.The main conclusions are as follows:(1)It is more reasonable to adopt the pantograph combination model for the analysis of pantograph aerodynamic characteristics.Through the numerical simulation analysis and comparison of the aerodynamic characteristics of different pantograph combination models under the action of cross wind,it is concluded that the aerodynamic resistance of the pantograph combination model with the ripple facing forward is the smallest,reducing by about 9.3%,the aerodynamic noise is reduced by about 2d B,and the aerodynamic noise of the model with the ripple symmetrically distributed along the outside is the smallest,reducing by about 3d B,Aerodynamic noise mainly depends on the disturbance degree of air flow around the surface.(2)When there is no cross wind,the aerodynamic simulation analysis of different pantograph combination models shows that when the operation mode of the same pantograph combination model remains the same,when the pantograph changes from two position end to one position end,the aerodynamic resistance of different pantograph combination models increases by about 4.2% on average,and the aerodynamic characteristics are better when the pantograph is in two position end.(3)Keep the installation position of the pantograph unchanged.When the pantograph changes from open to closed operation,the aerodynamic resistance of different pantograph combination models increases by about 15% on average.When the pantograph changes from closed operation to open operation,the average change of aerodynamic lifting force of different pantograph combination models is 75.5% and the maximum decrease is 92.6%.In order to ensure good contact between pantograph and catenary,In general,the aerodynamic characteristics of closed operation of pantograph are good.(4)Under the same operating condition without cross wind,the existence of the corrugated structure of the carbon sliding plate at the pantograph head reduces the aerodynamic resistance of the pantograph,especially when the corrugated is located on the windward side of the carbon sliding plate at the front and rear of the pantograph head,and the pantograph is located at the two position end.When the pantograph is closed,the aerodynamic resistance decreases the most,about 5.1%.The corrugated structure of carbon sliding plate at the pantograph head has a good noise reduction effect when the pantograph is located at the two position end of the middle vehicle and closed operation.(5)Comparing the aerodynamic forces of the two pantograph combination models under different operation modes and whether there is cross wind,it is concluded that the existence of cross wind reduces the influence of pantograph operation mode on its aerodynamic characteristics,but also reduces the aerodynamic performance of pantograph.By analyzing the effect of pantograph raising angle on the influencing factors of pantograph components,it is concluded that when the pantograph raising angle is about17 °,the impact of pantograph components on the aerodynamic lifting force of the whole pantograph is relatively small,and it is most unlikely to lead to excessive pantograph catenary contact force.