A comparison of three conceptual design approaches applied to an electric distributed lift aircraft

This paper serves as an introduction to a collaborative effort between the U.S. Army U.S. Army Combat Capabilities Development Command (DEVCOM) Aviation and Missile Center, ONERA, and DEVCOM Army Research Lab. Each organization employs their conceptual design toolchain (NDARC, CREATION, or HYDRA) on a common set of geometry. Initial weight, drag, and power estimates on this aircraft for a common sizing mission and set of assumptions were provided along with a component-based comparison of weight and drag estimates for each tool. Broad agreement for the baseline mission requirements was observed for all three tools. Design sensitivities showed substantial differences in performance estimates vs forward flight speed which has broader design implications. Wingspan and rotor radius were varied and optimized for each tool with different behavior for each. NDARC predicted that a larger wingspan would reduce aircraft weight with little impact from changing the rotor radius. CREATION and HYDRA predicted that reducing the wingspan and increasing rotor radius would reduce aircraft weight. The different design conclusions from each tool reflect uncertainty in evaluating the structural and aerodynamic performance of similar systems with complicated interacting aerostructural behavior when using conceptual-level tools. Areas for further tool development were also identified.