Pterodactyl: Aerodynamic and Aeroheating Database Development for Integrated Control Design of a Mechanically Deployed Entry Vehicle

摘要

The Pterodactyl project explores different control system architectures for the precision landing of a Deployable Entry Vehicles (DEV). Aerodynamic control surfaces hinged at the edge of the heat shield, to change the vehicle's angle of attack and side slip, are one of the architectures being analyzed. Computational Fluid Dynamics (CFD) simulations at multiple levels of fidelity are performed to construct aerodynamic databases for an asymmetric variant of the Adaptable, Deployable, Entry Placement Technology (ADEPT) and the integrated Flap Control System (FCS) at discrete deflection angles. A component-based approach is applied for the reporting of aerodynamic loads and moments on the vehicle and the multiple control surfaces. These aerodynamic databases are utilized for stability, control and guidance analysis. NASA-developed aerodynamic simulation software CBAero and Cart3D are used for engineering-level and higher-fidelity simulations, respectively. The use of Cart3D is necessary to resolve the numerous shock interactions on the control surfaces. The higher-fidelity Cart3D solutions are used to anchor the initial CBAero databases. Improved heating and aerodynamic load estimates are attained from the anchored CBAero databases. In conjunction with a trajectory, the anchored CBAero databases provide heat load estimates and additional data for the sizing of the vehicle's Thermal Protection System. When longitudinal flaps are fully deflected for angle of attack modulation, the control surfaces have the authority to trim the vehicle at an angle of attack of approximately -20 degrees with a Lift-to-Drag ratio of 0.35 in the hypersonic regime. When lateral flaps are fully deflected for side slip modulation, the control surfaces have the authority to trim the vehicle at a side slip of approximately -17 degrees, an indication of potential for significant cross range control. Finally, high heating is predicted on the edges of forward-deflected control surfaces. This paper presents the methods for geometry modeling, CFD simulations, post-processing, and relevant results for this class of DEV.