Effects of usage dimpled surfaces on Ahmed body jeneric model flow characteristics

Vehicle aerodynamics which directly affect fuel consumption values in vehicles, has a great importance in terms of vehicle stability, acceleration ability, vehicle noise and environmental pollution. The Ahmed car model is one of the most important generic models so this popular car model is widely used in the literature on fluid mechanics and vehicle aerodynamics studies. The simple and easy applicable shape of the Ahmed body make the model convenient in these sort of investigations. This study investigates effect of a passive drag reduction technique which it is known as dimple surface, on Ahmed car model with 35° slant angle. In order to take distinctive result, rear wake zone was selected for design optimization area. The flow control methods were applied numerically also these methods were compared with similar works. The selected passive drag reduction method was used with different model configurations to determine optimum parameters and evaluate these parameters how will effect on the vehicle drag and lift coefficients. Analyses made in this study, were calculated with 2.4 million cell number and the maximum drag value reduction was obtained as 3.5 % by using dimple surfaces. Moreover, the applicability and manufacturability factor was also evaluated in terms of implementing the dimpling modification to today's current road vehicles and in order to make this study meaningful for vehicle aerodynamics.