Airfoil Shape Optimization Using NURBS Representation Under Thickness Constraint

Results for 2D airfoil shape optimization in transonic regime are presented. A Navier-Stokes flow solver is used to compute the flow-field. Single-point and multipoint formulations of the optimization problem are proposed and compared. A NURBS representation of the airfoils allows smooth optimized airfoils to be obtained which do not experience severe performances losses in off-design condition. The multipoint formulation, combined with the NURBS representation, allows to obtain airfoils with good performance over a specific Mach range. A design of experiment is conducted to determine the most sensitive design variables in order to reduce their number in the optimization process.