Uncertainty Analysis of Fluid-Structure Interaction of a Deformable Hypersonic Inflatable Aerodynamic Decelerator

摘要

The objective of this paper is to present the results of a detailed uncertainty analysis for high-fidelity fluid-structure interaction modeling of a deformable hypersonic inflatable aerodynamic decelerator at peak heating conditions for lifting Mars entry with a turbulent flow assumption. Uncertainty results are presented for the structural deformation response and surface conditions (pressure, shear stress, and convective heat transfer) of the inflatable decelerator with an efficient polynomial chaos expansion approach. The uncertainty results are compared with results obtained in a previous study for ballistic Mars entry. Approximately half of the flowfield and structural modeling uncertainties show at least 90% combined contribution to the inflatable decelerator deflection and resulting surface condition uncertainties. For lifting Mars entry, global nonlinear sensitivity analysis shows that the tensile stiffness of the inflatable structure's axial cords and radial straps and the torus torsional and tensile stiffnesses are the main contributors to the inflatable decelerator deflection uncertainty. As a result of these structural uncertainty contributions, the shape deformation contributes up to 10% of the uncertainty in the surface conditions. However, the freestream density dominates the uncertainty in the surface conditions experienced by the inflatable decelerator. In addition, the CO2-CO2 binary collision interaction is a significant contributor to aerodynamic heating and shear stress uncertainty.