CFD Toolkit for Modeling Parachutists in Freefall

A recent increase in the occurrence of pilot parachute deployment hesitation events during training has focused attention on the flow field about parachutists in freefall. An improved understanding of this flow will contribute to better equipment and improved safety. Computational Fluid Dynamics (CFD) analysis is a powerful technique for exploring such flows. Once validated against experimental data, CFD solutions may be used to probe the flow in detail and to evaluate the effects of changes in body position or equipment configurations. In Phase I of this project, we demonstrated each step of a simplified modeling approach and validated it against a detailed CFD model and against published experimental data. In Phase II we will implement an innovative Freefall Toolkit that separates the expensive and time-intensive CFD flow solution generation process from the trajectory simulation process. The result is a front end Simulator Tool that may be used interactively to explore the freefall dynamics of specific configurations while detailed solutions are generated off-line in a batch process. We will conduct a detailed validation of our solution process for a number of specific cases before extending the parameter space to cover a wide range of drop conditions and configurations. Our Freefall Toolkit, to be delivered at the end of the Phase II project, will enable researchers, designers, and freefall instructors to better understand the complex flow field about a parachutist in freefall and hence contribute to improved equipment designs and safer freefall practices.