What is it about?
We compared OSPREE’s in situ Vis-NIR spectra from Varda W-2 (340–800 nm: N2, N2+, NO, and the O 777 nm line) with shock-layer radiance computed from SPARTA (DSMC), LAURA (CFD), and HARA (radiation) between 85 km and 55 km (about Mach 28 to 20). SPARTA tracks the flight data well from 85–75 km. LAURA overpredicts radiance above 65 km by up to a factor of two. Atomic oxygen at 777 nm is underpredicted along the whole trajectory, consistent with breakdown of the quasi-steady-state assumption and local continuum breakdown above ~70 km.
Featured Image
Why is it important?
This is a rare side-by-side of continuum CFD and kinetic DSMC against the same in situ reentry spectra. It shows that a single method does not cover the transition regime, and that electron number density in LAURA–HARA is a likely driver of the high-altitude radiance overprediction. That is a concrete target for the next round of model work.
Perspectives
If you only read one of the W-2 modeling papers, start with OSPREE (the measurements) then this one (how the codes fare along the trajectory).
Zach Davis
Space Dynamics Laboratory
Read the Original
This page is a summary of: Comparing Aerothermodynamic Models With Emission Spectroscopy Data From the Atmospheric Reentry of the W-2 Hypersonic Testbed Vehicle, January 2026, American Institute of Aeronautics and Astronautics (AIAA),
DOI: 10.2514/6.2026-0307.
You can read the full text:
Contributors
The following have contributed to this page
