| Along with our country's scientific and technological progress and economic development,China's annual volume is relatively large,in order to meet the growing traffic,increase the amount of the construction of high-speed railway in our country,but China's diverse topography is complex,especially in the northwest,southwest,mountainous area is large,this creates the phenomenon of these regions have a larger tunnel line,especially the train entered the tunnel aerodynamic problems.The aerodynamics of high-speed trains can be divided into two categories,one is the aerodynamics of trains on the open line and the other is the aerodynamics of trains passing through the tunnel.The main content of this paper is tunnel aerodynamics.At present,there are three main research methods for the aerodynamics of high-speed railway tunnels at home and abroad: theoretical analysis,numerical calculation and real vehicle test.Numerical calculation can be divided into using a one-dimensional flow model for numerical calculation,or using a three-dimensional flow model for calculation.Compared with the two,the one-dimensional flow model has lower cost and is more flexible in the selection of operating parameters.In this paper,Fortran software was used to carry out numerical simulation calculation with the source code program of tunnel pressure wave numerical simulation of one-dimensional characteristic line flow model.In order to prove the reliability of the calculation in this paper,after determining the parameters,the calculation results of the calculation method in this paper were compared and verified with the actual vehicle test results at home and abroad.In this paper,the research model is the Chinese standard emu CR400 AF,and when the single-track tunnel and double-track tunnel of different lengths are passed by the single-track tunnel and the double-track tunnel at 250km/h and 350km/h speeds,the regularity of the position and time of the maximum value in the tunnel and the time of any measuring point in the tunnel are studied.Based on the maximum positive pressure value in the tunnel,the maximum negative pressure value in the tunnel and the maximum pressure peak-peak value in the tunnel,the most unfavorable tunnel length is summarized.The main conclusions are as follows:(1)At 250km/h speed,the position of the maximum positive pressure value in the tunnel is the same as the distance from the tunnel entrance,and the maximum positive pressure value in both single-lane and double-lane tunnels appears before the train leaves the tunnel.The maximum negative pressure in the tunnel appeared before the train left the tunnel.The peak-peak position of the maximum pressure in the tunnel is basically consistent with the position of the maximum negative pressure under most working conditions.The maximum positive pressure at any measuring point appears near the exit of the tunnel when the train leaves the tunnel,and the maximum negative pressure at any measuring point in single-and-double-line tunnels of different lengths appears before the train leaves the tunnel.(2)The law of the maximum positive pressure inside the tunnel is different between single-line tunnel and double-line tunnel under the speed level of 350km/h.The position of the maximum negative pressure value in the single-line tunnel and the double-line tunnel is approximately the same as the distance from the tunnel entrance.The peak-peak position of the maximum pressure in the tunnel is basically consistent with the position of the maximum negative pressure under most working conditions.(3)The length of the most unfavorable tunnel based on the three maximum values in the tunnel all shows a trend of decreasing with the increase of the speed.The most unfavorable tunnel length based on the maximum pressure peak-to-peak value in the tunnel is the same as that based on the maximum negative value in the tunnel.When the 16 marshalling emu passes,the tunnel length greater than 8 marshalling emu passes based on the most unfavorable tunnel length of the three minimum values in the tunnel. |
PDF Full Text Request