Wind tunnel probe into the low aspect ratio wings of assorted configurations for micro air vehicles

Abstract Micro air vehicles (MAVs), a class of unmanned air vehicles, usually have low aspect ratio ( AR ) wings and operate in the range of low Reynolds number ( Re ). In this study, the effect of AR and Re on the performance of low AR wings have been carried out in a subsonic wind tunnel to generate lift, drag and pitching moment data. This obtains sufficient insights into the understanding of MAV aerodynamics. The force measurements are done for the low AR wings composed of S5010 and E214. The AR in each case was varied in the range of 0.5 to 2.0, whereas the Re was varied in the range of 80 × 10 3 to 120 × 10 3 . The effect of Re on the lift is found to be more prominent in the post-stall region for all AR s except 0.5. This study also indicates that with a decrease in AR , the impact of Re on performance becomes less pronounced. As the AR reduces, the maximum lift coefficient and the lift-to-drag ratio of the wings drop significantly. Similarly, the slope of the lift curve also decreases with a decrease of AR . Furthermore, for a given AR , the induced drag factor of both wings decreases with increasing Re , while at a fixed Re , it increases as AR decreases. In contrast, the stall angle shows an improvement with the reduction of AR and it is more prominent for the wing of E214 airfoil. The pitching moment values become more negative with an increase of AR , indicating the pitch-down tendency of the wing to rise with AR .