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Low-aspect ratio wings possess different characteristics compared to the high-aspect- ratio ones with long spans. By decreasing the aspect ratio (defined as AR=b/c, where b is the wingspan and c is the averaged chord of the wing), trailing/tip vortices become more influential over a large portion of the wing and modify the aero/hydrodynamic performance of the wing. As a result, by decreasing AR, the lift slope decreases [27]. Here, turbulent flows over a low-aspect-ratio wing (AR=1) with NACA 0012 airfoil sections are simulated at a  high Reynolds number Re ~1.5x10° (Fig. 7). In this regard, a well-converged grid with about 1 million elements is utilized. The computational domain is extended to 4 and 10 times the  wingspan in x and x° directions, respectively. In addition, the domain is extended 3 times of the wing span in the lateral directions to minimize the boundary effects.   Fig. 7. Formation of the tip vortices on a low-aspect-ratio wing with NACA 0012 airfoil

Figure 7 Low-aspect ratio wings possess different characteristics compared to the high-aspect- ratio ones with long spans. By decreasing the aspect ratio (defined as AR=b/c, where b is the wingspan and c is the averaged chord of the wing), trailing/tip vortices become more influential over a large portion of the wing and modify the aero/hydrodynamic performance of the wing. As a result, by decreasing AR, the lift slope decreases [27]. Here, turbulent flows over a low-aspect-ratio wing (AR=1) with NACA 0012 airfoil sections are simulated at a high Reynolds number Re ~1.5x10° (Fig. 7). In this regard, a well-converged grid with about 1 million elements is utilized. The computational domain is extended to 4 and 10 times the wingspan in x and x° directions, respectively. In addition, the domain is extended 3 times of the wing span in the lateral directions to minimize the boundary effects. Fig. 7. Formation of the tip vortices on a low-aspect-ratio wing with NACA 0012 airfoil