Evaluating Aerodynamic and Propulsive Performance of a Wing with Distributed Electric Propulsion

Distributed electric propulsion (DEP) has gained significant attention for its potential to enhance aerodynamic and propulsive performance by leveraging the interaction between several propellers and the aircraft wing. To identify suitable DEP configurations and operating conditions, a wind tunnel investigation was conducted using an eight-propeller DEP system and a three-dimensional wing at a chord-based Reynolds number of 350,000. Aerodynamic load measurements were obtained using a six-axis load cell for the wing and single-axis load cells for each propeller. The DEP system was placed in several tractor, pusher, and over-the-wing (OTW) configurations. The thrust of each propeller was maintained at specific values while propeller advance ratios were varied. The results demonstrated that the tractor and OTW configurations augmented lift by as much as 32% and 26%, respectively, while a simultaneous increase in propeller efficiency was only observed in the tractor configuration. Moreover, lift augmentation was further enhanced using a nonuniform thrust distribution where more thrust was allocated near the wing root. Regarding overall efficiency, a tractor configuration with propellers below the leading edge and an OTW configuration near 30% of the airfoil chord had the highest efficiency when operating at cruise and higher thrust, respectively.