Adaptive FSI of flexible parachutes under strong dynamic loading using strongly coupled shell mechanics and large-eddy simulation with analytical curvilinear hybrid meshing

Future robotic and human space missions to planets and moons in the solar system will involve entry vehicles with higher masses than that of any currently available vehicle. Slowing down these vehicles during entry, descent, and landing (EDL) into the atmosphere is in part accomplished by using deployable light-weight parachutes, although they have limited robustness. This proposal concentrates on the development of high-fidelity physically-based computational models of flexible parachutes. Their dynamics must be accurately predicted by the computational model, specially during the challenging phase of deployment and inflation. Unsteady forcing of the parachute by the afterbody flow must be predicted accurately to evaluate the stability and integrity of the structure for a wide range of conditions in a cost-effective manner. The flexible structure of the parachutes is made of composite woven fabrics of strong fibers impregnated in a polymer matrix and exhibit anisotropic nonlinear constitutive behavior. We proposed the development of a novel high-fidelity fluid-structure interaction (FSI) computational tool that can be applied to the analysis of subsonic and supersonic parachutes under the strong dynamic loading conditions encountered during deployment (where failure modes seem to concentrate). The physical elements implemented in the tool include turbulence modeling by large-eddy simulation, nonlinear structural shell mechanics, and robust contact treatment. Furthermore, a novel hybrid gridding idea will be demonstrated to dramatically reduce current FSI time-to-solution costs. This research will help NASA by providing with a unique tool to help in the design of parachutes at a reduced cost and effort