Document Type : Primary Research paper
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.