Multidisciplinary Exploration of DRAGON: an ONERA Hybrid Electric Distributed Propulsion Concept

Aero-Propulsive Efficiency Requirements for Turboelectric Transport Aircraft

“…Numerous studies on hybrid-electric propulsion have been performed in recent years, with the goal of reducing emissions [1][2][3], reducing operating costs [4], or enabling new missions for which aircraft were traditionally not competitive [5]. A large fraction of these studies focuses on regional [6][7][8][9][10] and short-or long-haul [11][12][13][14][15][16][17][18][19] commercial transport aircraft, since these markets constitute the dominant contribution to the environmental impact of aviation [20], and a radical change in the design of these aircraft is required in order to meet the long-term sustainability goals established by the European Commission [21] and NASA [22]. However, multiple studies have already shown that this step-change is a difficult task for large passenger aircraft, even when assuming appreciable advances in electrical-component technology with respect to the current state-of-the-art [9,14,15].…”

A Review of Concepts, Benefits, and Challenges for Future Electrical Propulsion-Based Aircraft

“…The propulsors can be spread in multiple fashions, such as in the leading edge of the wing [56,57], over-the-wing [58][59][60], under-the-wing [59,61], on the wing-tip [57,62], and on the fuselage-aft [26,53,63] to realize aero-propulsive synergistic integration benefits. Such benefits can be materialized in multiple ways: a lower size wing, better cruise performance, a shorter take-off and landing length etc.…”

“…Furthermore, the synergistic effects between the DEP system and the airframe are explored, establishing a suitable sizing methodology under the umbrella of this project [54]. Distributed fans research aircraft with electric generators by ONERA (DRAGON) conceptual design represents a DP architecture with ducted fans distributed along the wing span in a hybrid electric configuration aircraft carrying 150 PAX [61]. The study uses 2D aerodynamic analysis for locating the fans and utilizes propulsive flap concepts for high-lift requirement.…”

Aerodynamic Performance and Interaction Effects of Circular and Square Ducted Propellers

“…Ducted rotor systems have also gained significant interest in recent years in the field of (hybrid-electric) distributed propulsion [7,8]. Hybrid-electric aircraft concepts employing distributed ducted systems include over-the-wing [9], under-the-wing [10], and boundary-layer ingesting [11] configurations, as well as several urban air mobility concepts [12]. However, despite the strong influence of the design of the ducted propulsion system on the aerodynamic characteristics of the aircraft, the shape of the duct is generally not investigated in conceptual design studies [9,11], and is only obtained on a case-specific basis through high-fidelity optimizations (see e.g.…”

“…Ref. [10]) later in the design process. This is mainly because, in a broader sense, it is unclear what the optimal duct shape is for a generic propulsion-system arrangement.…”