Experimental study of the effect of blade curvature and aspect ratio on the performance of a rotary-wing decelerator

Abstract

The effects of different blade configurations on a vertically falling rotating blade decelerator (pararotor) are studied. A pararotor model equipped with cambered plate blades with different curvatures was tested in a wind tunnel. The parameters measured were flow velocity, rotation velocity, the drag generated by the model, and the blade pitch angle. The parameters selected for the analysis of the results were the drag coefficient of the model and the velocity ratio (ratio between the falling and rotation velocities). These parameters were determined and compared with those obtained for flat-plate blades. Flat-plate blades with different aspect ratios were also tested and analyzed. The results obtained show that the velocity ratio increases with camber, and the equivalent drag coefficient remains unaltered by camber and aspect ratio variations.