Accession Number : ADA264115


Title :   A Computational Model That Couples Aerodynamic and Structural Dynamic Behavior of Parachutes during the Opening Process


Descriptive Note : Final rept. Oct 91-Jan 93,


Corporate Author : ARMY NATICK RESEARCH DEVELOPMENT AND ENGINEERING CENTER MA


Personal Author(s) : Stein, Keith R ; Benney, Richard J ; Steeves, Earl C


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a264115.pdf


Report Date : Apr 1993


Pagination or Media Count : 32


Abstract : In parachute research, the canopy inflation process is the least understood and most complex to model. Unfortunately, it is during the opening process that the canopy often experiences the largest deformations and loadings. The complexity of modelling the opening process stems from the coupling between the structural dynamics of the canopy, lines and payload with the aerodynamics of the surrounding fluid medium. The addition of a computational capability to model the coupled opening behavior would greatly assist in the understanding of the canopy inflation process. ongoing research at the U.S. Army Natick Research, Development and Engineering Center (Natick) focuses on this coupled problem. The solution to the coupled problem is expected to assist in the development of future U.S. Army airdrop systems which include the capability of deploying at low altitudes and high speeds. A computational fluid dynamics (CFD) code and structural dynamic mass spring damper (MSD) code are coupled with an explicit marching method. The CFD flow solver provides the differential pressure values at node points along a radial which are used as input in the MSD model. The MSD code integrates the equations of motion for the canopy and returns current nodal positions and velocities to the CFD code. The node points on the MSD model coincide with a unique set of adjacent CFD grid points for all time. This coupled model predicts behavior for a quarter-scale C-9 parachute which compares favorably with experimentally determined behavior....Parachute models, Computational fluid dynamics, Aerodynamic Characteristics, Mass spring damping system, Structural analysis, Fluid-structure interaction, Parachute opening.


Descriptors :   *AERODYNAMIC CHARACTERISTICS , *PARACHUTES , VELOCITY , INPUT , PAYLOAD , EQUATIONS OF MOTION , OPENING(PROCESS) , MODELS , INTERACTIONS , DYNAMICS , MASS , STRUCTURAL ANALYSIS , DEFORMATION , GRIDS , STRUCTURES , DAMPING , MOTION , COMPUTATIONAL FLUID DYNAMICS , NODES , COUPLINGS , OPENINGS , ALTITUDE , FLUID DYNAMICS , ARMY , EQUATIONS , VALUE , FLOW , BEHAVIOR , CANOPIES , TIME , ENGINEERING , SCALE , PRESSURE


Subject Categories : Aerodynamics
      Gliders and Parachutes


Distribution Statement : APPROVED FOR PUBLIC RELEASE