Unsteady aerodynamic optimization of a morphing airfoil

This thesis work presents an approach to aerodynamic optimization of harmonically deforming morphing thin-airfoils. The frequency domain Kussner and Schwarz unsteady aerodynamic theory is extended to compute aerodynamic forces and power using a piecewise cubic representation of the camberline displacements, since this general formulation is able to model a wide range of shapes. To compute the inertial and elastic contributions to the actuation power, the airfoil is treated as an Euler-Bernoulli beam, and mass and stiffness matrices are computed with a Ritz-Galerkin approach, using hermitian finite elements as shape functions. Optimizations are performed with both genetic algorithms and sequential quadratic programming methods. Single-objective optimizations are performed on the aerodynamic moment. Multi-objective optimization are carried out to minimize the aerodynamic moment and the power (aerodynamic power or actuation power). Every optimization takes into account a lift constraint. Results are computed at different reduced frequencies.