Fluid-Structure Interactions of a Round Parachute: Modeling and Simulation Techniques

A parallel computational technique is presented for carrying out three-dimensional simulations of parachute  uid-structure interactions, and this technique is applied to simulations of airdrop performance and control phenomena in terminal descent. The technique uses a stabilized space-time formulation of the time-dependent, three-dimensionalNavier–Stokes equations of incompressible  ows for the  uid dynamicspart. Turbulent features of the  ow are accounted for by using a zero-equation turbulence model. A Ž nite element formulation derived from the principle of virtual work is used for the parachute structural dynamics. The parachute is represented as a cable-membrane tension structure. Coupling of the  uid dynamics with the structural dynamics is implemented over the  uid-structure interface, which is the parachute canopy surface. Large deformations of the structure require that the  uid dynamics mesh is updated at every time step, and this is accomplished with an automatic mesh-moving method. The parachute used in the application presented here is a standard U.S. Army personnel parachute.