Subway Train Piston Wind Numerical Simulation

The problem of piston wind is causing extensive concern with the quick developing of the subway in subway of city. And it has become one of the important subjects in the field of subway due to the speeding up of the train. Firstly, mechanism of piston wind was analyzed when subway train was moving in the tunnel. The physics and mathematics models of subway train are established on basis of the certainly simplification and assumption. A three dimensional turbulent flow is studied by the computation of the incompressible N-S governing equations . the finite-volume method was used to discrete the equations.Secondly, on account of the train motion in numerical simulation, dynamic mesh approach is developed in this paper . The key advantage of this approach is that the meshes interpolated in the computation domain is utilized to remap the flow variables from the old mesh to the new. The stability and efficiency for coupled structure-fluid time marching computations have been emphasized in mesh deformed algorithm. Exercise the regulation of the train was compiled the procedure of UDF in C language .Thirdly, the piston wind was simulated in the subway zone tunnel, compare the numerical results with theory calculation and measure, the rationality of physics mathematics model and the method of computation were validated.Finally, three-dimension physics and mathematics models of subway train were established about the Zhu-jiang station of Nan-jing, Based on the numerical simulation , the velocity and pressure were analyzed and the distribution characteristics of piston wind was generalized.The dynamic study on the distribution of velocity and pressure in the tunnel and station with the numerical simulation is the first time in the domestic. The thesis achieves regulation of the piston wind and the important theories meaning with practical values that accelerate the research of the aerodynamicist and thermodynamics of the subway network system.