Flexibility as parameter of model parachute performance characteristics

Abstract

Abstract : Parachute model tests offer the possibilities of efficiently conducting parametric performance studies. Meaningful model experiments must, however, consider besides the effects of Reynolds and Mach Numbers, those of porosity as well as structural characteristics if non-steady processes shall be investigated. In the following the model stiffness index is defined and its effect upon static and dynamic performance characteristics investigated. Quantitative data and stiffness indexes of cloth samples and parachute models are determined. A new technique of construction is described which provides parachute models with a lower stiffness index than previously available. Results of wind tunnel and catapult experiments with parachute models of different stiffness indexes are shown and, when possible, compared with results of full size tests.