Investigation of the effect of module design on the velocity and temperature distribution of the interior of the light rail vehicle

In this paper, a numerical investigation of local thermal comfort of passengers in a light rail vehicle (LRV) was performed by using Computational Fluid Dynamics (CFD) method. A virtual manikin model was developed and added to the numerical model which include convection and radiation heat transfer between human body and environment. In the numerical simulations, air flow and heat transfer characteristics were computed with steady-state conditions. The numerical simulation was performed considering TS EN 14750-1 standard described the thermal comfort conditions for different climatic zones of railway vehicles and two different cases were employed. The comparison of the numerical results to the experimental data obtained from this study was also presented and discussed. The numerical results were in good agreement with the experimental data used in this study. Railway vehicle cabin include five different parts called as module and each modules had different properties such as passenger capacity and seating arrangement etc. Thus, the effect of different module design on the velocity and temperature distribution of railway vehicle was investigated. The numerical results shown that the local heat transfer characteristics of the human body had significant importance to design an effective central heating, ventilation and air conditioning (HVAC) system. From the numerical results we shown that each module had different heat transfer and air flow characteristics and each passenger had different thermal sensation properties due to different seating arrangement in each module and these differences can be evaluated by using TSENS index. The numerical analysis developed in this study will be used as a reference study for scientific researches in the HVAC engineering of LRV vehicle. Another important result is that using a single air flow channel did not meet the thermal comfort demands for all passengers in this railway vehicle. Unlike, different air flow channel design configurations should be considered and developed for these vehicles.