Multi-objective System Optimization of Suborbital Spaceplane by Multi-fidelity Aerodynamic Analysis

An effective approach has not been established for the reusable launch vehicle, particularly for spaceplanes, whereas the conceptual design method has been established to some extent for aircraft. Spaceplanes that have wing like airplanes flight various environment, and the airframe and trajectory design problem are closely linked. Therefore, the multidisciplinary optimization method is required to optimize the airframe and the flight trajectory design at the same time in the spaceplane conceptual design. Due to computational cost constraints, a low-accuracy Computational Fluid Dynamics (CFD) method was used in a previous study to evaluate the aerodynamic characteristics of the airframe. This has been a source of concern regarding the accuracy of optimization calculations. In this study, a multi-fidelity approach is applied where the low fidelity and high-fidelity CFD are used in a complementary way. This surrogate model was connected into the manned spaceplane’s Multidisciplinary Design Optimization (MDO) framework. As the load limit was reduced, the wing area grew larger and the initial mass increased.