Research on 2D airfoil optimization design method for distributed ducted fan and wing blended configuration

The distributed ducted fan and wing-blended configuration has emerged as a key direction for green aviation due to its boundary layer ingestion advantages. However, its strong aero-propulsive coupling renders traditional design methods ineffective, while existing numerical simulations face a dilemma between the prohibitive computational cost of high-fidelity models and the insufficient physical fidelity of simplified models. To address this, this paper first proposes and validates an aerodynamic dimensionality-reduction design concept, based on which a two-dimensional (2D) momentum source method with interface zoning characteristics and a rapid optimization framework is established. By partitioning the interface into boundary layer, wake, and mainstream zones and introducing a mass flow correction factor, the method effectively compensates for the absence of streamtube contraction effects under 2D assumptions. Validation against full-aircraft 3D MRF simulations demonstrates that the prediction error for airfoil pressure distribution is within 1.2%, while computational efficiency is improved by approximately 200 times. Optimization studies reveal that geometric features such as “upper surface flattening” and “local contraction upstream of the inlet” effectively suppress separation. Results indicate that the maximum lift-to-drag ratio of the optimized configuration is increased by approximately 50%, fully validating the engineering value of this design framework in the conceptual design phase.