Wing Aerodynamic Analysis Incorporating One-Way Interaction with Distributed Propellers

Abstract

The use of electric motors on general aviation aircraft may enable new aircraft designs that are noticeably different from conventional configurations due to the reduced weight and volume of electric motors compared to conventional engines. One potential design involves distributing multiple propellers over the wing span to augment lift at low speeds. This paper describes initial conceptual design-level work in modeling the aerodynamics of wing configurations with multiple tractor propellers distributed upstream of the leading edge. The approach leverages a vortex lattice model of the wing aerodynamics and propeller slipstream velocities obtained from the XROTOR code augmented with corrections based on the Conway actuator disk model. The technique captures only the "one-way coupling" between the propellers and the wing in which only the propellers' impact on the wing is considered. This method provides quick results that may aid in design space exploration of DEP concepts in the conceptual design stage. Results indicate that substantial lift improvements may be obtained through leading edge propellers. Furthermore, distributing an equivalent amount of total power over four propellers instead of two provides additional increases in wing lift augmentation even when the propeller design and diameter are held fixed. These results should be verified with more detailed analyses that can capture the full mutual coupling between the wing and all propellers, but these initial tests indicate promise for distributed propeller configurations to provide lift augmentation at low speeds.

Design and Performance of the NASA SCEPTOR Distributed Electric Propulsion Flight Demonstrator

“…A future paper will detail the low-order integrated aerodynamic-propulsion modeling approach used for the "cruisesized" wing analysis, along with the subsequent validation of this approach to higher-order computational methods. A companion paper by Patterson et al [15] describes the design of the high-lift propeller system, which has been built up from previous work [6,7,16,17,18,19]. …”

A Surrogate-Based Multi-Disciplinary Design Optimization Framework Exploiting Wing-Propeller Interaction

“…As a matter of fact, this reduction is perceived by the wing itself, so that if a certain swirl is present in the flow approaching the leading edge of the wing, swirl recovery already occurs in the first chord-wise stations, so that points closer to the trailing edge will perceive a lower swirl. This effect becomes crucial when modeling propeller-wing systems with different tools, as the negligence of the mentioned phenomenon brings to an overestimation of the wing lift distribution variation [1] [19].…”

Aeroelastic Stability Analysis of Electric Aircraft Wings with Distributed Electric Propulsors

“…Moreover, distributing several motors along the wing might be helpful in alleviating the gust loads-actively or passively [6]. Several research projects on distributed propulsion aircraft have been undertaken, however, there reamins room for further investigations [7]. Leifsson et al [6] carried out a multidisciplinary design optimisation of a blended-wing-body transport aircraft with distributed propulsion.…”

“…They showed that using distributed propulsion increased the lift-to-drag ratio of the wing. Patterson and German [7] considered an initial conceptual aerodynamic design of a wing with several propulsors distributed along the wing span. It was concluded that lift improvement could be obtained by using leading edge propellers.…”