CFD investigation on lift and drag coefficients on a car at various angles of rear diffuser

Cars have been important part of life for nearly a century. Many design iterations have been made since its emergence to improve its efficiency and extract more work. Some of the improvements include downsizing the engine, improved engine and transmission efficiency, using fluids like oil and coolant to resist phase change in extreme temperature conditions and for the aerodynamic losses like changing the vehicle shape to make it more streamline. The vehicle shape not only affects the efficiency but also the stability in using it at high speeds. The major objective of the present work is to design the various diffuser sections for a vehicle and to determine the Coefficient of drag, coefficient of lift, drag force and lift force of a vehicle through computational fluid dynamics analysis. A diffuser was added at the rear end of the vehicle and simulation studies were carried out for different diffuser angles of 0^o, 6^o, 9^o and 12^o. Lift coefficient in the downward direction should be high, which is desirable to prevent over turn at high-speed usage. The obtained data is analyzed and plotted to select the considerable diffuser section to be used to achieve the permissible lift and drag forces.