Abstract
An experimental investigation into the aerodynamics of a ring wing has been carried out in an low speed wind tunnel, at a Reynolds number of 215,000. A flying toy that has a rim on their outer edge was selected as a model of the ring wing to examine the effect of rim on the aerodynamic performances when the flow comes from the trailing edge of the airfoil. The lift and drag coefficients shows that the ring wing with the rim has a good performance in the reversed flow, resulting low drag characteristics at a flight angle of attack. CFD analysis revealed that the separated vortex from the rim makes the streamline smooth and thereby set their drag lower than the case without rim at the same airfoil.
