Diagnostics of 3D Dynamic Stall on Rotor Blades

Abstract

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Leading-Edge Flow Structure of a Dynamically Pitching NACA 0012 Airfoil

“…Yet, despite intensive efforts, it has so far resisted a complete physical description due to a unique combination of flow unsteadiness, three-dimensionality, nonlinearity, and inviscid/viscous interaction [2,18,19]. An airfoil that experiences an unsteady increase in angle-of-incidence that carries it beyond its static stall angle is known to develop an increase in lift, without a noticeable change in lift-curve slope [11].…”

Leading Edge Flow Structure of a Dynamically Pitching NACA 0012 Airfoil

“…The unsteady phenomenon, coined dynamic stall, has attracted significant interest because of its potential to enhance the maneuverability and performance of aircraft, as well as its intimate connection with helicopter aerodynamics. Yet, despite intensive efforts, it has so far resisted a complete physical description due to a unique combination of flow unsteadiness, three-dimensionality, nonlinearity, and inviscid/viscous interaction [2,18,19]. An airfoil that experiences an unsteady increase in angle-of-incidence that carries it beyond its static stall angle is known to develop an increase in lift, without a noticeable change in lift-curve slope [11].…”