Freestream Reynolds Number Effects on Supersonic Retropropulsion: a CFD Analysis

Supersonic Retropropulsion (SRP), a technique involving the use of retro-thrust during supersonic flight, represents an effectve technique for decelerating and landing high-mass payloads on Earth and other planets. This study investigates how avaliable wind tunnel SRP data are scaled up to flight conditions using CFD analysis, focusing on freestream Reynolds number effects in a single-nozzle, axisymmetric configuration. A Reynolds average Navier-Stokes (RANS) model is validated against experimental and numerical data, then applied to a larger-scale configuration representative of a reusable launch vehicle. Results, including Schlieren imaging and spectral analysis, show a reduction in flowfield oscillation frequency as model size increases, indicating significant scale-dependent aerodynamic behavior.