Derivation of Aeroelastic Sensitivities and Their Verification for 2-DoF Airfoil in Incompressible Flow

Abstract

This report derives the equations for the stability sensitivities of aeroelastic models with regard to design parameters. The equations are verified for a 2-DoF airfoil model in incompressible flow. For that purpose, the derived equations are applied to Theodorsens aerodynamic theory which includes the derivatives of the unsteady aerodynamic forces as well as the derivative of Theodorsen's function. Moreover, the aeroelastic sensitivities are derived in modal coordinates which renders them applicable to state-of-the-art aeroelastic wing and aircraft models. The verification of the modal and aeroelastic sensitivities also includes the comparison to numerically obtained finite difference approximations.