Investigating Dynamic Stall of Low-Aspect Ratio Wings with Different Airfoils

The dynamic stall of wings is a complex phenomenon that depends on various parameters, including airfoil geometry. In this study, we compare the dynamic stall mechanisms of low-aspect-ratio wings with three distinct airfoil geometries at a chord-based Reynolds number of 250,000. These three geometries exhibit static stall characteristics known as trailing-edge separation, leading-edge separation, and thin-airfoil stall. The wings are oscillated using a recently developed three-degrees-of-freedom robotic system equipped with an internal six-axis load cell. We also measure the flow field using high-speed planar and stereoscopic particle image velocimetry over the spanwise center and across the wake region, respectively. The results identify differences in the dynamic stall behavior of the three airfoils and the resultant forces, and shed light on the correlation between load and measured flow features during dynamic stall.