Numerical investigation of the aerodynamics of the REX-Free Flyer in the rarefied gas regime

The REX-Free Flyer is a concept study by the German Aerospace Center (DLR) in an effort to develop an orbital experimental platform to fill the gap between short duration experimental facilities and long-term missions at the International Space Station. The envisioned reusable vehicle shall enable day- and week-long experiments in high-quality weightlessness. The unique sharp-edged geometry promises improved aerodynamic properties. A soft and controlled re-entry shall guarantee a recovery of the experimental setup.The Direct Simulation Monte Carlo (DSMC) method is used to simulate a Mach 20 nitrogen flow around a scaled-down model of REX in the rarefied gas regime. First, a brief overview of the implemented numerical and phenomenological models in the in-house code DSMC code PICLas is given. Simulation parameters ensuring physical results are presented. Consequently, the code is used to investigate the lift, drag, and pitching moment coefficients at five different angles of attack: 0°, 14°, 28°, 40°, and ...