Improved aerodynamic-propulsion interaction model for distributed-electric-propulsion system and its integration in sizing for hybrid-electric distributed-propulsion aircraft

Currently, there is a growing global demand for electric propulsion aircraft, driven by the objectives of carbon peaking and carbon neutrality. Distributed-electric-propulsion (DEP) aircraft, notable for improved aerodynamic and propulsive efficiency through aero-propulsive coupling, have attracted much attention. A key research direction of this configuration is to develop DEP aero-propulsive integration models applicable to the sizing design of DEP aircraft. However, the predictive accuracy of current models is limited, as they neglect the effects of flap deflection and variations in the wing’s effective aspect ratio. To address these issues, an improved model is proposed that incorporates these factors for a more accurate prediction. Validation is performed by comparing the aerodynamic coefficient augmentation predicted by the proposed method with those from other methods, and experimental and high-fidelity CFD data based on different configurations. The results show that, compared to the baseline model, the improved model provides predictions that achieves closer agreement with CFD and wind tunnel data. Subsequently, the improved model is integrated into a previously developed sizing framework for electric propulsion aircraft, to facilitate hybrid-electric distributed-propulsion (HEDP) aircraft sizing design. Specifically, the updated terms are incorporated into the sizing matrix plot (SMP) module and flight performance module, highlighting their interconnection with sizing design system. The X-57 case study indicates that, compared to the design with baseline model—which underestimated the actual configuration’s maximum takeoff mass (MTOM) by 3.31 %—the design using improved model achieves a reduction of the relative deviation from the actual MTOM to 2.06 % by simulating aerodynamic force coefficient increments more precisely and assessing the aircraft’s power requirement and energy consumption more reasonably, thereby enhancing the accuracy of design parameter evaluations.