Experimental assessment of an airfoil optimized to delay the onset of dynamic stall

Rotor blade aerodynamics are significantly influenced by dynamic stall. This study is part of a larger effort to delay the adverse effects of dynamic stall on rotor blade aerodynamics through airfoil shape optimization. This paper summarizes the experimental results of this effort. Time-accurate surface pressure measurements along with lift and moment coefficients were determined experimentally for the baseline and optimized airfoil geometries at relevant conditions. Particle Image Velocimetry was also utilized to shed light on the state of the flow on the two airfoils at select conditions. The sensitivity of dynamic stall under different flow conditions was studied for both airfoils. The result indicate significant improvements in the behavior of the optimized airfoil geometry. Approved for public release: distribution unlimited