Numerical simulation to optimize the position of subway's shaft

To consider the influence of ventilation shafton environment and pressure change in the subway and optimize the shaft's position,the three-dimensional unsteady numerical analysis using the moving mesh and the sliding interface method was carried out when the shaft situates on the acceleration segment,the uniform motion segment and the deceleration segment of trains.The results show that the numerical result of the tunnel without any shaft agrees with the foreign experimental data.It is extremely beneficial to utilize train-induced piston to exclude the heat when the shaft locates on the uniform motion segment of trains and near to the outlet of station.Meantime the maximum pressure amplitude and the pressure gradientof the inlet could also decrease effectively,but the maximum pressure amplitude and the pressure gradientof the outlet would increase.To take the effect of shaft on ventilation and aerodynamics into account,the shaft should be placed on the uniform motion segment of trains and near to the outlet of station with consideration of the running mode of trains.