Applications of an Analytic Stall Model to Time-History and Eigenvalue Analysis of Rotor Blades

A dynamic analysis of a single-section model of helicopter blade is performed including an analytic model of dynamic stall. This stall model, a simplified version of the model introduced by Tran and Petot, characterizes the lift force on the blade section throughout both the linear and non-linear regimes of angle of attack. The resultant, nonlinear blade equations are solved by numerical integration for the periodic, forced response. Perturbation equations, written for small disturbances about this equilibrium, provide eigenvalue and stability information by means of Floquet theory.