Aero-Propulsive Interaction Effects on Wing Structural Sizing in Distributed-Propulsion Aircraft

Abstract

Distributed electric propulsion (DEP) modifies the spanwise lift distribution through propeller slipstream interaction, directly affecting wing-root bending loads and structural sizing. This paper extends a mid-fidelity aero-propulsive–structural framework to evaluate wing structural sensitivity for distributed-propulsion hybrid-electric regional aircraft with multiple propellers at arbitrary spanwise locations. Blade pitch trimming under non-uniform inflow is incorporated to obtain physically consistent slipstream velocities, and a three-dimensional numerical vortex-image correction replaces the previously used analytical jet correction to remove geometric constraints and enable flexible propulsion layouts. The objective is to quantify which propulsion-integration parameters govern wing structural mass and to assess whether clean-wing structural sizing assumptions remain valid for DEP configurations. The framework is applied to a representative 70-passenger hybrid-electric regional aircraft under cruise and 2.5𝑔 pull-up conditions. Results show that wing mass is governed primarily by spanwise load redistribution and associated bending-moment arm effects. Parameters that shift lift outboard are structurally penalising, while inboard redistribution reduces mass. Propeller rotational direction and thrust-share allocation emerge as first-order drivers, producing mass variations up to ∼ 3%, whereas swirl magnitude, spanwise translation, and disk-area changes are secondary within the investigated design space. Clean-wing aerodynamic loads are therefore not universally conservative and can underpredict structural mass depending on thrust distribution and propulsor placement. These findings demonstrate that propulsion-integration decisions must be evaluated jointly with structural sizing in conceptual DEP aircraft design