Low-Reynolds number aerodynamic response of a NACA0012 airfoil in os-cillatory motion

¹ Aerospace Engineering, Middle East Technical University, Northern Cyprus Campus, Güzelyurt via Mersin 10, 99738 Kalkanlı, Türkiye
² Berlin School of Business & Innovation, Artificial Intelligence, 12043 Berlin, Germany

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 12 March 2026

Abstract

Unsteady aerodynamic phenomena associated with plunging and pitching airfoils are of great importance in understanding biological flight, energy harvesting, and next-generation unmanned aerial systems. While numerous studies have explored these mechanisms at low Reynolds numbers, there remains a gap in systematically linking validated low-Re experiments to higher Reynolds regimes using high-fidelity numerical methods.

In this study, we investigate the unsteady lift and drag behaviour of a NACA 0012 airfoil undergoing pure pitch and pure plunge motions. An incompressible 2-D flow model is developed in OpenFOAM and validated against well-established low Reynolds number (Re ≈ 1000) benchmark cases from the literature for static cases. The developed framework achieved a high accuracy (≈ 95%) across angle-of-attacks between 1-30^°. The computational setup reproduces key parameters such as lift and drag coefficients, allowing direct comparison with existing experimental and numerical data.

After successful validation, the Reynolds number is kept constant to examine emerging flow features for pitch-ing and plunging motion, such as wake deflection, vortex shedding patterns, and their impact on aerodynamic performance. The results highlight how unsteady aerodynamic benefits evolve pure pitching and plunging modes, providing valuable insight for efficient propulsion and flow-control strategies for the future studies.