Laminar airfoil aerodynamic optimization design based on Delaunay graph mapping and FFD technique

In this paper, a free-form deformation (FFD) parameterization method is established based on the non-uniform rational B-splines (NURBS) basic function, and a multi-block structure grid deformation technique is established by the Delaunay graph mapping method. By coupling the parameterization method, the grid deformation technology and computational fluid dynamics (CFD) with particle swarm optimization (PSO) arithmetic, an aerodynamic optimization design system is constructed. This system is applied to a laminar airfoil design of high altitude long endurance (HALE) aircraft. The aerodynamic characteristic object function is evaluated by solving Navier-Stokes equations, and the γ-Rē _θt transition model coupling with shear stress transport (SST) turbulent model is introduced to numerically simulate boundary layer transition. The aerodynamic characteristics of the optimized airfoil show that the laminar airfoil aerodynamic optimization design system established in this paper has high efficiency and application value for the airfoil design of HALE aircraft.