Unsteady two and three-dimensional flow simulations of an oscillating airfoil are performed using the Lattice-Boltzmann CFD approach. A sliding mesh is employed, in order to reproduce the experimental wind tunnel setup. Parametric studies are performed to investigate wind tunnel effects. Results compare favorably with experimental data and other DES simulations in the literature. The flow structures are investigated in order to understand the change in aerodynamic coefficients with the presence of no-slip side walls, which are shown to have a strong effect in the results. It is seen that large, coherent flow structures are responsible for dynamic stall, but small, three-dimensional flow structures are the cause for chaotic variations in aerodynamic coefficients among pitching cycles.
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