Advances and challenges in cross-domain vehicle structures and morphing configuration design technologies

By the virtue of its design orientation of“ multi-functionality” and efficient repeated flights in large airspace and wide speed range, the cross-domain vehicle is of epoch-making significance in the field of aerospace and is becoming one of the focuses of technological competition among various countries. Due to the high frontier and comprehensive nature of this field, there is no clear technical route to realize the large envelope cross-domain vehicle, but it is generally agreed that the morphing configuration is the key technology and necessary means. In this paper, we discuss the conceptual routes to achieve cross-domain vehicle from four aspects, namely, the basic configuration, the morphing mode, the optimization of the morphing structure, and the thermal protection, with the morphing configuration as the main theme. We analyze the technology pavements and reference values provided by the existing researches on the design of cross-domain vehicle, and summarize the respective technological advances and challenges. Firstly, several basic configurations with application potential are introduced, and the differences in aerodynamic performance and volumetric ratio are compared; secondly, the structural design and aerodynamic impacts of different schemes are analyzed according to the classification of wings and head-cones; then, three levels of structural optimization techniques, passive and active thermal protection structural designs are introduced from the perspective of improving the deformation, load-bearing, and thermal protection performance of the morphing structures; finally, we summarize the challenges and problems that are still facing in the work of cross-domain vehicle structures and morphing configuration design, and look forward to the future development direction of related research.