Study On The Influence Of Piston Wind On Subway Safety Gate System Of Environmental Control On Ventilation Effect

Takeing the provincial sports station of secend line of Xi'an subway network of as prototype, establishes 3 dimensional geometric model was to study the flow within the station and tunnel incompressible, unsteady turbulent flow. Standard k-εequations are chosen and the finite volume method is used to control equations. Dynamic grid technique and discretion "Porfile" document make adopted to simulate procedure the train movement in different stage. In numerical simulation process both flexible smoothing and local re-drawing were combined for generating grid.The boundary conditions of tunnel entrances, the vents of the rail roof and bottom and the escalator entrance are set at free flow and pressure outflow.Besides through comparing these two kinds of boundary conditions, we can get more reasonable and accurate boundary condition. Trough numerical simulation, we can obtain releasing flow and exhaust heat effect of piston exhaust outlet, head track exhaust outlet, rail foot exhaust outlet, and this caused by the changes of the velocity and temperature fields within sector tunnel and in subway platform in the process of uniformly retarded motion at different early speed,meanwhile we can know the influence regulation in velocity and temperature fields in escnalators inlet and outlet generated by piston wind. By analyzing the effect to subway platform's velocity and temperature fields generated by piston wind in different height of Subway security door and through analysis, we obtain velocity distribution and temperature distribution's features in longitudinal direction, horizontal direction and lateral direction, and also we obtain the change regulation of wind speed follow different time in Stairs, escalators, entrances and exits, The safe door system that analyzes a result to express 2.2 meters height under the influence of piston wind smaller.