Analysis of Heat Transfer Inside Vehicle Cabins on the Basis of the Contribution Ratio of Indoor Climate

The contribution ratio of indoor climate (CRI)-an index of the spatial distribution of the thermal influence of heat sources-has previously been proposed as a means to estimate the individual contribution of heat sources to the temperature field in a room. In the present study, the CRI was used to predict the distribution of air temperature in vehicle cabins, and this simple prediction method was validated. Both convective and radiant heat transfer coefficients were calculated through computational fluid dynamics modeling, following which the entire thermal environment was evaluated. The equivalent temperature was predicted using prior knowledge of only the CRI and the airflow velocity. The results can be applied to increase the efficiency and decrease the energy consumption of air-conditioning systems.