Analysis of induced interior air flow in subway train cabin due to accelerating and decelerating

Abstract

Due to the importance of air-conditioning system in public transport vehicles, some researches focused on improving the efficiency of Air Conditioning (AC) systems, especially in urban and high speed trains. This study investigates the induced airflow in long corridor of metro train in accelerating and decelerating modes, analytically and experimentally. The simplified governing equation of Navier-Stokes for a three-dimensional time-dependent viscose flow is solved analytically using mixed method of separation of variables and Duhamel integral. The pure closed form solution is introduced and compared with experimental data in real Metro train with good accuracy. Finally the effects of this airflow on the performance and efficiency of the train's ventilation system is tested, analyzed and discussed to depict the homogenization of air temperature alongside the train. The results of this study can be used as benchmark for other numerical analysis and as a base for design of the train ventilation system.