CFD-Based Aerodynamic Optimization of an Unmanned Aerial Vehicle Wing Structure

Abstract

Unmanned aerial vehicles (UAVs) require aerodynamically efficient wings to increase endurance, payload capability, range, and operational stability while preserving low structural mass and manufacturability. This methodology paper presents a computational fluid dynamics (CFD)-based procedure for optimizing a fixed-wing UAV wing structure at low-to-moderate Reynolds number. The proposed approach combines parametric computer-aided design, mesh-independence assessment, Reynolds-averaged Navier-Stokes (RANS) analysis, transition-sensitive turbulence modeling, design-of-experiments screening, and multi-parameter aerodynamic optimization. Aspect ratio, taper ratio, tip twist, sweep, and wingtip device geometry are treated as principal design variables, while lift coefficient, drag coefficient, lift-to-drag ratio, pitching moment, and surface-pressure distribution are used as performance metrics. The k-omega SST model is selected as the baseline turbulence closure because of its suitability for adverse pressure gradients and separated flows, with a correlation-based transition model recommended for lower Reynolds-number cases. A step-by-step optimization framework is formulated to maximize aerodynamic efficiency while satisfying minimum lift, geometric thickness, stability, and manufacturability constraints. Representative demonstration results show the type of improvement expected from the workflow, including reduced drag and increased lift-to-drag ratio in the cruise condition. The methodology is intended as a reproducible framework that can be implemented in ANSYS Fluent, STAR-CCM+, OpenFOAM, or comparable CFD platforms and then coupled with structural finite-element analysis when aero-structural optimization is required.