Experimental and Computational Fluid Dynamics Study of Hayabusa Reentry Peak Heating

In this work, near-infrared and ultraviolet spectroscopic data collected during the Hayabusa spacecraft reentry is used as the basis for validating numerical and experimental studies using the compressible flow computational fluid dynamics codeEilmer3and the University of Queensland's X2 expansion tube. Spectra generated numerically from simulations of the full-scale vehicle at the selected trajectory point at 1 s after peak total heating were compared with experimentally captured spectra over a binary-scaled and total-enthalpy-matched radiating shock layer around a 1/5-scale Hayabusa model, and both sets of data were compared with spectra obtained from flight. For the infrared results, experimental and simulated spectra, as well as simulated and flight spectra, compared well within an uncertainty margin of between 20 and 90% depending on the particular case being compared. Experimental and simulated ultraviolet results did not compare well; however, comparisons between simulated and flight ultraviolet spectra were more favorable, comparing well within an uncertainty of around 50%.