Vehicle aerodynamics has been the subject of extensive research, with a heavy
emphasis on the vehicle. Heavy vehicles, such as trucks and buses, have
undergone aerodynamic studies in recent years to reduce drag and improve fuel
economy [1]. In this study, the
distribution of air conditioning in the cabin of a passenger bus was
investigated by discussing the factors that influence in attaining the desired
thermal comfort values such as temperature distribution, relative humidity
ratios, and air velocities inside the bus. The research was conducted on three
different cases. In this study, different types of air-conditioning (AC)
outlets—linear grills, slots diffusers, and gaspers—were used, and the effect of
each outlet on temperature distribution, air velocities, and relative humidity
ratios within the bus was investigated. In all three cases, the inlet air
velocity was set to 0.8 m/s, and the return air was combined in the middle of
the bus. Finally, comparisons were made between the cases to determine the best
case for achieving the thermal comfort rates inside the bus. The results
demonstrated that the slots diffuser could not be used in the bus air
conditioning because of the presence of turbulences and swirl motions which
impeded the flow of cold air. The gasper is the best flow outlet in the air
distribution inside the cabin that achieves the required thermal comfort for the
passengers because the flow is laminar and there is no turbulence, resulting in
a good mixing between the conditioned air and the air inside the bus cabin and a
good distribution of temperature inside the bus.
