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arXiv · 2602.00285

Defects, Corrugation and Temperature Govern Rarefied-Air Drag on Graphene Coatings

Samuel Cajahuaringa·Davide Bidoggia·Maria Peressi·Antimo Marrazzo
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Abstract

In rarefied atmospheric environments, where continuum fluid dynamics breaks down, aerodynamic drag is governed by gas-surface momentum exchange, making surface structure and chemistry key design knobs. Using molecular dynamics simulations, we show that coating the $\alpha$-Al2O3(0001) surface with graphene markedly reduces the tangential momentum accommodation coefficient (TMAC) of N2, shifting scattering toward more specular reflection and thereby lowering drag; we further benchmark this response against graphite. The reduction strengthens up to 900 K. While structural defects can increase TMAC via defect-induced corrugation and local atomic and electronic rearrangements, graphene retains its performance at experimentally relevant defect densities.

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Samuel Cajahuaringa, Davide Bidoggia, Maria Peressi, Antimo Marrazzo. 2026-01-30. Defects, Corrugation and Temperature Govern Rarefied-Air Drag on Graphene Coatings. https://doi.org/10.1063/5.0325392

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