Cooling analysis of a long distance bus cabin using experimental and numerical methods

Abstract

Vehicle manufacturers are on a continuous challenge of increasing the fuel efficiency of their vehicles. Considering the energy withdrawn, the air conditioning unit stands as an important component to be investigated for increasing the overall efficiency of vehicles. In this study, the computational fluid dynamics (CFD) model of a long distance bus cabin is numerically validated by the experimental data obtained from a full scale bus tested in a climatic chamber. In the numerical methods, a transient analysis is conducted using ANSYS Fluent® numerical solver with employing realizable k-ε method and boussinesq approximation under the considerations of time-dependent temperature boundary conditions at the inlets, convection boundary conditions at the window and adiabatic walls. The results, however, indicate that the consideration of heat absorbed by the seat materials, convective heat transfer and conductive heat transfer from the walls are of great importance in the validation of a cabin cooling procedure under transient conditions.