Experimental Investigation of Parachute Canopies with Rectangular Parallelepiped Geometries

A series of wind-tunnel experiments were conducted in which the drag characteristics and inflated geometry of model parachute canopies with rectangular parallelepiped geometries (polyhedron) were examined. The model-canopy layouts were the same as cross canopies with the adjacent sides completely attached together. All models had a base dimension of 0.2 m, and aspect ratios ranged from 0.2 to 1.2. The models did not have a central vent or any other geometric porosity. The data show the inflated geometry of the canopy differs from the constructed geometry with the smallest change occurring at a constructed aspect of 0.8 and the variation becomes larger for increasing or decreasing constructed aspect ratios. The data also indicate the aerodynamic drag coefficient, based on the projected area, has a maximum value of approximately one for the constructed aspect ratio of 0.3 corresponding to an inflated aspect ratio of 0.53. The drag coefficient is less for smaller and larger aspect-ratio models. If scaled by ...