Preliminary Study On Aerodynamic Effect Of Ballastless Track Structure Of High-Speed Train

High-speed railway is a system supported by multiple disciplines.Since the construction and development of high-speed railway,its maximum operating speed has been continuously refreshed.Aerodynamics of high-speed railway is one of the key basic science and technology.As the speed demand of high-speed railway continues to increase,it is important to study and improve the aerodynamic response of high-speed railway.The main contents of modern highspeed railway aerodynamics are to study the aerodynamic characteristics of the train,the air distribution characteristics around the train and the interaction between the train and the surrounding environment.The research and design of ballastless tracks for high-speed railways adapted to higher operating speeds is of great significance for optimizing and improving the aerodynamic effects of high-speed railways and ensuring the safety of line operation.In this paper,the research topic is to study the effect of the high-speed railway ballastless track on the aerodynamic force of the train under the single-car operating condition of400km/h open line of the passenger high-speed railway.The three-dimensional,unsteady,compressible N-S equation and k-ε two equation turbulence model are used,the ballastless track of high-speed train is simulated and calculated in the form of slip grid.The main research contents are as follows:(1)A high-speed railway-ballastless track aerodynamic effect analysis model is established,the shape of the high-speed train and the selected ballastless track is reasonably simplified,and the spatial geometric relationship between the train and the ballastless track,and the boundary conditions between the train and the track are considered.The calculation of the aerodynamic characteristics of the train is realized in the form of the FLUENT dynamic slip grid,and the wind pressure and wind speed distribution of the high-speed train,the wind pressure distribution of the track,and the aerodynamic data of the train are post-processed,and the distribution characteristics of the aerodynamic force during the operation of the highspeed railway are analyzed.,and verifies the accuracy of the high-speed railway-ballastless track aerodynamic model.(2)Select CRTS Ⅲ slab ballastless track structure standard.Carry out the train-track aerodynamic simulation calculation for the design model,design five speed conditions of400km/h,450km/h,500km/h,550km/h and 600km/h,obtain the aerodynamic data of the train,and compare the data results.,to analyze the influence of speed increase on the aerodynamic force of high-speed railway.(3)Set up three analysis conditions: CRTSⅠ ordinary slab track,CRTSⅠ frame slab track,and CRTS Ⅲ slab ballastless track,and compare and analyze the three typical ballastless track structures in relation to the shape irregularities of the three ballastless track structures.The aerodynamic effect of the shape on the train is considered,and the comprehensive performance of the three ballastless track systems is considered to determine the optimal high-speed railway aerodynamic ballastless track structure.(4)Taking the CRTS Ⅲ slab ballastless track as the research object,the main structure of the ballastless track surface was adjusted,and the ballastless track of the high-speed railway was studied under the conditions of heightening and widening the ballastless track for a speed of 400km/h.The aerodynamic problems of high-speed trains under conditional operation are compared with the aerodynamic effects,and reasonable suggestions for improvement are put forward.