Analysis of unsteady airflow in a subway station influenced by train movement

Abstract

The piston effect has a significant effect on ventilation systems in subway stations. In this article, experimental data and computational fluid dynamics (CFD) methods are used to examine the behavior of the unsteady airflow generated by train movement. The experimental data recorded in an actual station in the Tehran subway and a full-scale model were used for the numerical simulation. The simulation was conducted using layering method to simulate the train movement through the tunnels and station according to the actual subway train velocity trend. Air curtains were used to reduce the undesired influence of the piston effect in the station and increase the efficiency of the ventilation system. The results indicated that maximum amplitude of air velocity at the subway entrance caused by the train movement can be reduced 67% by using an air curtain on the subway platform.