Adjoint Optimization of an Airfoil for Light STOL Freighter Aircraft

Abstract

An airfoil's lift coefficient (Cγ) is a critical parameter determining the amount of payload an aircraft can carry. The lift-to-drag (L/D) ratio then determines the fuel efficiency and range with a defined payload. For those reasons, it is beneficial to optimize the airfoil used on the wings of an aircraft. In this paper, the adjoint optimization of the Cγ of an airfoil for light freighter aircraft is discussed. The CASA C-212 Aviocar aircraft with its NACA 65(3)-218 airfoil was chosen for the optimization. The optimization uses the assumptions of inviscid incompressible potential flow, allowing the use of the panel method for flow solution. Verification computations imply, that the optimization results are relevant even in the compressible and viscous flow.