Experimental Study On The Influence Of Positive Impact Of Pitting Network Location In High-speed Railway Tunnel

With the rapid development of high-speed railway(HSR)in China,the requirements of operation and management of high-speed railway catenary are significantly increasing.In light of the managerial experiences in different areas at home and abroad,we explore and summarize the safe operation rules of HSR catenary.Our studies on the characteristic experiments of the impacts of positioning and attitude of the HSR catenary at tunnel portal start with the previous malfunctions of catenary at the Beijing-Guangzhou HSR.In view of machine vision theory,we implement the real-time monitoring and early warning of the movements,uplift offset parameters,and vibration volume of the HSR catenary with the aerodynamic effect of the tunnel using the area array CCD camera.Besides we also build a coupled train-tunnel-catenary model to investigate the structural parameter variation of test tunnel and the mechanism of the influence of the vibration offset on the HSR catenary.The maximum vertical and corresponding lateral offset values are computed from the real-time measurements for the HSR catenary at tunnel portal using the Yangji'ao tunnel in the HeWu HSR as a target.We also analyze the maximum vertical offset and the corresponding limitations of positioning slope for different HSR models(pantograph pitch)Based on the three-dimensional,compressible,and unsteady Navier-Stokes(N-S)equations,we use a flow field software to calculate the aerodynamic effects caused by the high-speed train passing through tunnel.The related motions between the train-tunnel structure are simulated using the Sliding Mesh technology.In addition,the sensitivity studies on the effects of tunnel length,vehicle speed and group length on the pantograph surface,surrounding flow field pressure,and pantograph aerodynamic moment are also conducted using numerical simulations.According to the main conclusions,the offset attitude detection for the HSR catenary at tunnel portal is very important to the study on the safety of the bow and the network under the tunnel aerodynamic coupling effect.