Wesley CONDREN, Chris HAMBIDGE, David STEUER, Anthony FINNERTY, Matthew McGILVRAY
DOI Number: N/A
Conference number: HiSST-2025-368
Roughness effects are of significant importance in the design of ablative thermal protection systems for atmospheric entry. In particular, the augmentation of skin friction increases the drag experienced by the vehicle. The drag over rough walls is a sum of both viscous and pressure effects, the latter dominating in the fully rough regime. Furthermore, these effects are typically understood through empirical correlations developed at subsonic conditions. This paper presents an experimental study into roughness-induced shear stress augmentation in hypersonic flow. The experiments were conducted in the Oxford High Density Tunnel at Mach 5 with a unit Reynolds number ranging from 44 – 60×106m−1 and a roughness Reynolds number well within the fully rough regime. Pressure sensitive paint was used to evaluate a spatially continuous surface pressure map over the roughness elements. Through integration, the pressure drag over the surface is calculated and compared to a direct shear stress measurement using a floating force balance.