Ladder Type Tunnel Buffer Structure On The Influence Of The Aerodynamic Effect Research

With the rapid development of science and technology,also conducted a number of train speed,entered the era of high-speed rail,with the increasing speed of the train,the train aerodynamics problem more and more serious,bring many negative effects to people,such as train tunnels,produce a lot of pressure fluctuations,affecting the traffic safety.So to solve the problem of train aerodynamics urgent need.In order to complex fluid flow can produce accurate simulation of high speed train entering into a tunnel,this paper solves the three-dimensional compressible unsteady N-S equations,k-two equation model,and the relative motion between the train and tunnel were simulated using the sliding mesh technique.Combined with numerical simulation,the aerodynamic effect of tunnel with step buffer structure is studied,and the following conclusions are drawn:As a step buffer structure is set at the entrance of the tunnel,the influence of the compression wave generated by the high-speed train entering the tunnel can be effectively relieved.The pressure gradient peak at the wall of the tunnel is also greatly reduced,and it has an effective mitigation effect on the weakening of the aerodynamic effect.In contrast to tunnel with step buffer structure in tunnel entrance,compared with tunnel without cushion structure,the pressure time history curve of initial compression wave is not smooth with step buffer structure,and the time section of pressure developing to maximum pressure increases.The number of steps buffer structure on the pressure rise ahead of time from morning till night is three order buffer structure is the earliest,the two order buffer structure of first-order buffer structure is the latest,and no obvious peak pressure gradient when the buffer structure is much smaller;in the step type buffer structure with same length and the same speed and order change when the three order buffer structure on the peak pressure gradient reduction optimal;change,in step type buffer structure,length of the same rate order is three,the length is 40 m buffer structure to reduce the pressure effect of optimal structure change;step type buffer,the optimal form three and form five decompression effect.The main research results of this paper is to analyze the train tunnel aerodynamic performance variation of the pressure inside the tunnel,provides the reference for the step type buffer structure design,step type buffer structure for tunnel tunnel construction and tunnel construction etc.