What is it about?
We simulated the hot shock layer around Varda’s W-2 reentry capsule with direct simulation Monte Carlo (DSMC), using first-principles quantum chemistry data for how air molecules transport energy, relax internally, and react. That chemistry set had not previously been used in a large-scale DSMC run of a real reentry vehicle. We then fed the flow field into NASA’s HARA radiation code and compared the predicted visible/near-infrared emission with in situ spectra from the OSPREE flight experiment at 78 km.
Featured Image
Why is it important?
Reentry heating and emission models still lean on legacy two-temperature CFD. Against the OSPREE flight spectra, the first-principles DSMC path improved total radiance prediction by about 30% over that CFD. At the altitudes where the flow is transitional, particle methods capture non-continuum effects that continuum CFD misses, which matters for radiative heating during vehicle design.
Perspectives
This is the modeling companion to the OSPREE flight paper: same vehicle, same spectra, but here the question is whether ab initio rates in DSMC actually move the prediction. They do, at least at 78 km.
Zach Davis
Space Dynamics Laboratory
Read the Original
This page is a summary of: Aerothermal investigation of an atmospheric reentry capsule using direct simulation Monte Carlo with ab initio rates for internal energy relaxation and chemical kinetics, Acta Astronautica, November 2026, Elsevier,
DOI: 10.1016/j.actaastro.2026.06.009.
You can read the full text:
Contributors
The following have contributed to this page
