Assistant Professor, Department of Aeronautical Engineering Nehru Institute of Technology, Coimbatore
A ball moving through air, experiences aerodynamic drag force. Dimpled balls fly farther than the non-dimpled balls due to reduction in drag. Because, dimpled surface cause boundary layer on upstream side of the ball to transition from laminar to turbulent. The turbulent boundary layer is able to remain attached to the surface of ball much longer than a laminar boundary layer and so creates a narrower low-pressure wake and less pressure drag. The reduction in pressure drag causes the ball to travel farther. So that, we have planned to analyse this dimpled surface feature on other aerodynamic shapes like airplane wings. In that, we are going to take NACA 0015 symmetrical airfoil shape. After fabrication we will test it and compare it with NACA 0015 without dimples. The information useful for solving aerodynamic problems of aeronautical, space and automobile applications are best obtained rapidly, economically and accurately by testing the scaled models in wind tunnels. The dimpled texture we are placing in a rectangular wing is arranged in an order (linear and staggered pitch), and the diameter of the texture is of about 0.4 inches (10mm) and the depth is 0.04 inches (1mm), where it should be in the accurate manner. After fabrication, for testing process we are using low-speed, open circuit, suction type wind tunnel and test section is 300mm*300mm. The contraction ratio is 91 and the axial flow fan is driven by AC motor.