Study of the flow around a bus model

Land transportation is the most widely used passenger and freight transportation in Turkey. It is known that a 10% drag reduction leads to approximately a 5% reduction of the fuel consumption of a bus at a common highway speed. An estimated total savings of $100 million per year can be recognized in Turkey alone for just a 5% reduction in fuel use in intercity passenger transportation by buses. Detailed knowledge of the aerodynamic characteristics of passenger vehicles could lead to find out new solutions to reduce fuel consumption and emissions and improving the vehicle performance and passenger comfort.In this study, flow structures around a rectangular body and two different bus models are analyzed using both particle image velocimetry (PIV) and flow visualization techniques. Measurements were performed at several planes which were selected to highlight the aerodynamic characteristics of the models. The instantaneous and time-averaged velocity vector maps, vorticity contours, streamline topology and turbulence characteristics of flow fields are presented.