Parks College Parachute Research Group

More Scaling Laws for Ram-Air Parachute Inflation

J. Potvin
Parks College Parachute Research Group
Saint Louis University, St. Louis, MO 63103

Presented at the 16th AIAA Aerodynamic Decelerator Systems Technology Conference and Seminar Boston, MA, May 2001, Paper AIAA-2001-2021


For decades parachute designers have used inflation scaling laws relating inflation time and opening shock to many deployment conditions and construction characteristics. Most of these laws, however, are relevant only to the basic circular parachute, with or without geometric porosity, and without opening shock control devices. In this note new inflation scaling laws on the effects of altitude and payload weight on the more modern ram-air parachute wings (or parafoils) are formulated and discussed. This analysis is a sequel to the numerical and experimental studies by Potvin and by Potvin, Peek and Brocato on the inflation of parafoils outfitted with a slider. These authors have also discussed the inflation scaling properties of ram-air parachutes but only with regards to changes of the canopy spreading rate constant and overall size.

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