Three-Dimensional Effects on Plunging Airfoils at Low Reynolds Numbers

We present two-dimensional and three-dimensional (3-D) direct numerical simulations of large-amplitude plunging maneuvers at Reynolds numbers 5000, with velocity ratios , 1, 2. For all cases, the evolution force coefficients is qualitatively similar. The lift coefficient presents a pronounced peak toward end acceleration phase maneuver, local minimum in deceleration phase, second maneuver. amplitude main increases linearly limited effect number negligible three-dimensionality flow. On other hand, both have stronger on maximum value as well subsequent transient decay static values. comparison flow structures near airfoil shows that these differences are due to subtle interactions between various vortices generated during development 3-D boundary layer suction side triggered by instability trailing-edge vortices.