Fluid-structure interaction simulations of the ASPIRE SR01 supersonic parachute flight test

Abstract

High-fidelity fluid-structure interaction (FSI) simulations of the ASPIRE SR01 supersonic parachute flight test are performed through the loose coupling of computational fluid dynamics (CFD) and computational structural dynamics (CSD) solvers. The CFD solver employs a Cartesian adaptive mesh refinement (AMR) grid paradigm with a ghost cell immersed boundary method to represent arbitrarily complex geometries, and the CSD solver uses MITC3 triangular shell and Timoshenko beam elements to discretize the parachute canopy and suspension lines. The CFD resolution required to capture the deficit of the dynamic pressure in the wake of the ASPIRE payload and the aerodynamic drag on the parachute canopy is systematically studied via grid refinement study before FSI simulations are conducted. FSI simulations presented consider the inflation of an initially folded parachute canopy in freestream conditions matching the line stretch event during the ASPIRE SR01 flight test. The total pull force at the instance of peak loading is predicted to within 10% of the flight test data. The sensitivity of the total pull force and canopy projected area to the grid resolution in the CFD and CSD domains is systematically studied via another grid refinement study, and grid convergence with respect to the CFD domain resolution is demonstrated. The pull force vs time curve predicted by each CFD and CSD grid resolution varies by less than 1% indicating a high degree of repeatability and low grid-related uncertainty. Remaining differences in the qualitative behavior of the pull force curve and quantitative difference in the peak pull force are thus determined to stem from modeling errors such as the lack of deceleration, and different initial parachute and flow states in the FSI simulations compared to the flight test.