Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 49 3 2017 10 23 Experimental Study of Drag Reduction on a Model Car Using an Active Flow Control Experimental Study of Drag Reduction on a Model Car Using an Active Flow Control 435 444 749 10.22060/mej.2016.749 FA A. Bak Khoshnevis Mechanical Engineering Department, Hakim Sabzevari University, Sabzevar, Iran V. Barzanooni Mechanical Engineering Department, Hakim Sabzevari University, Sabzevar, Iran Journal Article 2015 07 06 Aerodynamic drag is one of the most important determinants of vehicle’s fuel consumption. Pressure drag which is the main component of total drag is a result of boundary layer separation from vehicle surface. In this paper, we investigate experimentally, the possibility of separation from the upper surface of model and the effect of base bleeding as an active flow control method on aerodynamic drag reduction of Ahmed body with 35 degree rear slant angle. Then optimum position of blowing on the slope and vertical surfaces at the end of model was found. Blowing increased static pressure in the wake and reduces the drag. In addition, pressure profile across the surface model, velocity and turbulence intensity in this paper is studied. The results showed that the jet flow in the best position<br />causes 21 % reduction in the drag coefficient. If the jet flow is applied on the upper position of inclined surface, it increases the drag coefficient. All tests are done in an open circuit blowing wind tunnel with maximum turbulent intensity of 1 % and maximum speed of 30 m/s. Velocity measuring components are carried out by hot-wire flow meters. Aerodynamic drag is one of the most important determinants of vehicle’s fuel consumption. Pressure drag which is the main component of total drag is a result of boundary layer separation from vehicle surface. In this paper, we investigate experimentally, the possibility of separation from the upper surface of model and the effect of base bleeding as an active flow control method on aerodynamic drag reduction of Ahmed body with 35 degree rear slant angle. Then optimum position of blowing on the slope and vertical surfaces at the end of model was found. Blowing increased static pressure in the wake and reduces the drag. In addition, pressure profile across the surface model, velocity and turbulence intensity in this paper is studied. The results showed that the jet flow in the best position<br />causes 21 % reduction in the drag coefficient. If the jet flow is applied on the upper position of inclined surface, it increases the drag coefficient. All tests are done in an open circuit blowing wind tunnel with maximum turbulent intensity of 1 % and maximum speed of 30 m/s. Velocity measuring components are carried out by hot-wire flow meters. https://mej.aut.ac.ir/article_749_b056eb1587586b71e2da9acfe4fbd19e.pdf