Study on Airflow Characteristics of Train Induced by Piston Effect in Subway Tunnel

Abstract

The piston effect caused by the subway train running in the tunnel will cause the air flow to move along the direction of the train to form piston wind. The piston wind generated by the train when braking, starting and through tunnels of different lengths has differences. Combined with these influencing factors, the airflow organization characteristics caused by the train piston effect are studied in a typical single hole single line subway tunnel. Through the test: When the train brakes, the wind speed at both ends of the platform will quickly decrease. When the train starts, the wind speed at the front of the platform will gradually increase, and there will be no obvious change in the wind speed at the end of the platform. Through tunnels of different lengths, the wind speed response time at tunnel exit varies with the distance of train piston wind propagation.