Design and Aerodynamic Optimization of a Reusable Flight Vehicle Based on Divided Free-Form Deformation Parametric Modelling and Bayesian Optimization

Abstract The integrated design is of vital importance to the high-speed vehicle due to appropriate aerodynamic configuration under high-speed conditions. Especially, the blended wing body (BWB) design for integration pays great attention to the constraints of various geometric components. The free-form deformation (FFD) parameterization is wildly applied in the aerodynamic shape design as it can effectively control the variation in airfoils and reflect the transition effect of the wing-body fusion area, but take disadvantages on setting constraints for global deformation. In this study, a divided FFD parameterization that clearly distinguishes between the wing, the wing-body fusion and the fuselage in integrated design while maintaining geometric continuity is proposed. This clear definition helps to optimize the aerodynamic performance of each component while ensuring the overall design coherence and consistency. The parameterization proposed is applied to aerodynamic optimization under multiple flight conditions. A comparative analysis reveals that our method can effectively output the reasonable configurations. The optimization uses Bayesian optimization, with 50 iterations, and achieves stability after about 10 iterations. After optimization, the constrained wing section retains the geometric feature of the original configuration design, while the wing-body fusion forms a geometric transition between the two components. The lift-to-drag ratio of the reusable flight vehicle improves significantly across multiple angles of attack at an average of 32.6%.