A Numerical optimization technique for the design of airfoils in viscous flows

The present work involves the implementation of an efficient optimization procedure for the design of airfoils in viscous flows The scope of the work is limited to low Reynolds number, incompressible, and unstalled fluid flow. Cubic Bezier curves with corresponding polygons are employed to define the airfoil, the vertices of which are used as design variables in the optimization process. Inviscid conditions about the airfoil are determined using a traditional Hess-Smith-Douglas panel method. Boundary layer calculations are subsequently made based on the inviscid results and the solution is updated, thereby accounting for viscous effects. A hybrid Generalized Reduced Gradient/Sequential Quadratic Programming method is used in conjunction with the aerodynamic model, to optimize the airfoils. Results were obtained for maximum lift and minimum drag problems with and without constraints. The results of the optimization were validated using CFD