The effect of steady shear on the aerodynamic performance of an airfoil at low Reynolds number

The aerodynamics of steady airfoils in uniform flow has received considerably more attention than that of airfoils operating in a non-uniform flow. The current research experimentally investigates, using direct force measurements, the effect of shear in a steady approach freestream on the aerodynamic forces acting on a NACA 0012 airfoil over the angle of attack range of ±25°, and a chord Reynolds number range of 6×10³ to 3×10⁴. The uniform freestream case is compared with two different shear rates at each Reynolds number. There is an asymmetric effect of mean shear on the aerodynamic forces with regards to angle of attack. While some observed effects of shear and shear rate are consistent at different Reynolds numbers, other observations change with Reynolds number.