by

Helicopter rotor blades frequently encounter dynamic stall during normal flight condi-tions, limiting the applicability of classical thin-airfoil theory at large angles of attack. Also, it is evident that because of the largely different conditions on the advancing and retreating sides of the rotor, future rotorcraft may incorporate dynamically mor-phing airfoils (trailing-edge flaps, dynamic camber, dynamic droop, etc.). Reduced-order aerodynamic models are needed for preliminary design and flight simulation. A unified model for predicting the airloads on a morphing airfoil in dynamic stall is presented, consisting of three components. First, a linear airloads theory allows for arbitrary airfoil deformations consistent with a morphing airfoil. Second, to cap