Integrated Iterative Design Method for Ducted-Fan-UAV Rotor–Stator System with CFD-Coupled Correction

This paper presents an integrated iterative design methodology for the rotor–stator system of a hovering ducted-fan unmanned aerial vehicle (UAV). By synthesizing the foundational aerodynamic theory—momentum theory, blade element theory, and vortex theory—analytical formulas for the preliminary blade geometry are derived. To address the inherent inaccuracies of these idealized models, a computational fluid dynamics (CFD)-coupled correction loop is introduced, in which correction coefficients for the induced velocities at the rotor and stator are inversely calculated from high-fidelity simulation results and iteratively fed back into the analytical design framework. A design case study demonstrates the effectiveness of the method, with the iterative process significantly reducing the discrepancy between the design targets and high-fidelity CFD results. The method’s applicability is further supported by a comparative study using an alternative duct contour and by experimental validation on a physical prototype. These studies confirm that systematic correction based on high-fidelity analysis can reliably produce optimized designs from initially biased theoretical estimates, highlighting the potential of the methodology for practical engineering applications.