Optimization of mechanical deployable reentry vehicle based on multi-fidelity aerodynamic-trajectory coupling model

As the aerospace industry continues to advance, the demand for round-trip transportation between Earth and space, as well as deep space exploration missions, is increasing. The mechanical deployable reentry vehicle, a complex multidisciplinary system, experiences parameter coupling between trajectory design and aerodynamic simulation. The calculation of trajectory and the design of aerodynamic layout directly impact the flight process. To address issues such as biased trajectory data obtained without considering disciplinary coupling and the high computational costs associated with overall aerodynamic layout optimization, this paper fully considers the impact of global aerodynamic drag on the flight trajectory. A multi-fidelity optimization model for reentry vehicles, named Multi-Fidelity Aerodynamics-Trajectory Coupling (MF-ATC), is proposed. The model uses a large number of low-accuracy model samples to control computational costs, without considering the coupling relationship, and a small number of high-accuracy model samples to ensure approximation accuracy, achieving fast and precise prediction of flight trajectories. The results demonstrate that the MF-ATC model improves trajectory prediction accuracy and efficiently accomplishes aerodynamic shape optimization, effectively enhancing the vehicle's performance. The model shows great potential for engineering applications.