A simple, approximate model of parachute inflation

Conference · Wed Jan 01 04:00:00 EST 1992

OSTI ID:7068077

Macha, J M

A simple, approximate model of parachute inflation is described. The model is based on the traditional, practical treatment of the fluid resistance of rigid bodies in nonsteady flow, with appropriate extensions to accommodate the change in canopy inflated shape. Correlations for the steady drag and steady radial force as functions of the inflated radius are required as input to the dynamic model. In a novel approach, the radial force is expressed in terms of easily obtainable drag and reefing fine tension measurements. A series of wind tunnel experiments provides the needed correlations. Coefficients associated with the added mass of fluid are evaluated by calibrating the model against an extensive and reliable set of flight data. A parameter is introduced which appears to universally govern the strong dependence of the axial added mass coefficient on motion history. Through comparisons with flight data, the model is shown to realistically predict inflation forces for ribbon and ringslot canopies over a wide range of sizes and deployment conditions.

• Research Organization: Sandia National Labs., Albuquerque, NM (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 7068077
• Report Number(s): SAND-92-2282C; CONF-930580--1; ON: DE93002465
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420200* -- Engineering-- Facilities
Equipment
& Techniques
99 GENERAL AND MISCELLANEOUS
990200 -- Mathematics & Computers
ACCELERATION
AERODYNAMICS
DIFFERENTIAL EQUATIONS
DRAG
EQUATIONS
FLUID MECHANICS
MATHEMATICAL MODELS
MECHANICS
PARACHUTES
TESTING
TUNNELS
UNDERGROUND FACILITIES
WIND TUNNELS