Frontal resistance coefficient of the buses with the different ventilation equipment

The article presents the results of the investigation of the influence of natural and mechanical ventilation in the passenger compartment and in the driver's compartment on the air flow around the bus. Experimental research was carried out in aerodynamic tunnels. Based on the measurements, the air velocities distribution in the boundary layer is determined. Also, the effect of the natural ventilation of the interior space on the thickness of the air boundary layer is analysed. The results are presented in the form of distribution diagram and analytical dependencies. The aim of the research was to define the thickness of the boundary layer when the air flows through the vehicle model.