Improvment of a coach air-conditioning system by applying a distinct air channel

The aim of this study is to design an A/C air channel providing uniform air distribution along the coach, which has 12-m length and a capacity of 50 passengers. The air channel was designed by means of Computational Fluid Dynamics (CFD). In order to determine the most suitable turbulence model for the air channel properties, a turbulence model determination study was conducted with 5 different turbulence models, which are k-ε Standard, k-ε Realizable, k-ε RNG, k-Ω Standard, Spallart-Almaras, and the numerical results were compared with the experimental results measured from the experimental setup designed and produced. A grid independence study was also conducted to be sure that the solution is independent of grid. At the beginning of the study, cooling load of the coach calculated with a detailed study. After the cooling load calculations, a proper A/C unit selected, fitted to the vehicle and detail road tests, which includes measurements of underbody temperature distribution, A/C nozzle exit velocities, temperature distribution inside the passenger cabin and internal noise level, was performed to compare the current situation and final application. As a result of this study, passenger comfort was improved with the application of distinct air channel from uniform air and temperature distribution along the vehicle and internal noise level points of views.