Application of a State-Space Wake Model to Tiltrotor Wing Unsteady Aerodynamics

Presented at the American Helicopter Society Aeromechanics Specialists Meeting, San Francisco, CA, January 19-21, 1994.The Peters/He Finite State Wake Model is described in its application to fixed wing aerolasticity. Expressions for coupling this model with a wing, aerodynamically represented by a flat plate with a trailing edge flap, are developed, and fidelity issues are discussed. An application is presented where the wing/wake system is coupled to a proprotor model. The effects of unsteady wing aerodynamics on damping of this system are investigated. It is found that wake effects are small as a result of generally low damping levels in the system due to wing aerodynamic damping