Preliminary aerodynamic design of a reusable booster flight experiment

Abstract

The Reusable Flight Experiment (ReFEx) is an experimental vehicle currently in development by the German Aerospace Center (DLR), which simulates the reentry of a winged reusable booster stage. The topic covered in this paper is the aerodynamic design through the Mach number range from 5.0 to 0.8, including the transonic regime, by CFD simulations using the DLR TAU-Code. For steering and lift generation, the vehicle is equipped with multiple aerodynamic surfaces: canards, wings and a vertical fin. A VSB30 was chosen as the carrier rocket, leading to numerous limiting conditions that had to be fulfilled. The resulting tradeoffs are discussed. Also the process to achieve a configuration that meets all needs regarding stability during ascent and descent, controllability and energy management to autonomously follow a desired trajectory is explained. Since this vehicle is under development, the presented geometry is not necessarily the final shape. However, the completed design iterations strongly indicate that only details will differ between the presented state to the final and flyable ReFEx, scheduled to fly in 2022.