Air Ventilation and Comfort in Railway Vehicles Operating in Ventilation Mode

Abstract

This paper presents a computational fluid dynamics (CFD) analysis of the air and temperature distribution in a representative railway vehicle, with the objective of evaluating passengers' thermal comfort. The CFD model developed is featuring the wagon geometry in detail including air diffusers geometry, passengers, and luminaires. A set of different scenarios are studied, covering occupancy levels, state of the doors and windows (open/closed), inlet temperature, and air diffuser design. The results show a clear influence of the air supply system and design geometry on comfort, as local velocities well above 1 m/s were obtained for the original design. A new diffuser design proposed clearly improved the velocity field distribution enhancing passengers' thermal comfort. Exhaust vents are also presenting high velocities, which are significantly reduced down to 2 m/s when windows are open. It is observed that thermal comfort is not appropriate when air inlet temperature is conditioned to 19 °C, especially for the original diffuser design.