Conceptual design synthesis and multidisciplinary optimisation of unmanned combat aerial vehicles.

The purpose of this research is to investigate and develop conceptual design methodologies and computational tools appropriate to the design and analysis of low-observable Unmanned Combat Aerial Vehicles (UCAVs), performing a wide variety of missions, with various payload and performance requirements, as well as a wide range of operational constraints, from subsonic to high supersonic flight regimes. Undoubtedly, unmanned aircraft have transformed many aspects of aeronautics and aviation, with military applications often leading these transformational efforts. UCAVs have emerged as a potential strategy to counter technological, operational, and economical challenges to the future of aerial warfare. These challenges include an aging fleet of 4th generation fighters, the deployment of new, advanced 4+ and 5th generation platforms, the reported high vulnerability of current unmanned aerial vehicles, as well as the future development of hypersonic vehicles and weapons. In order to investigate future aircraft configurations, the GENUS aircraft design environment was envisioned by Prof. Howard Smith at Cranfield University’s Aircraft Design Group in 2012. This framework relies on a central architecture with high degrees of modularity and flexibility capable of designing, analysing, and optimising several species of aircraft with similar analysis tools, revealing the real differences and potential advantages of new designs. Mass estimation, propulsion, aerodynamics, performance, radar cross section estimation, and aero-thermal analysis tools have been integrated into the GENUS framework in order to investigate the design space of UCAVs. Validation of these methods has been hampered due to the often restricted access to quality data of UCAVs and similar configurations against which to compare and from which to generate higher fidelity models. Specific steps for improving the accuracy of the methods in the future have been identified and proposed in §9.2. Design space explorations performed in this research include a mission parameter trade study for subsonic UCAVs in Hi-Lo-Hi missions, the conceptual and preliminary design of a UCAV platform with performance matching that of current 5th generation fighters, a fully supersonic deep-interdiction mission trade study, and a high-supersonic (M ≥ 3.0) carrier-based UCAV for time-critical strike missions.