AIAA 2003-3957 Optimization of High-Lift Configurations Using a Newton–Krylov Algorithm

A gradient-based Newton–Krylov algorithm for aerodynamic shape optimization is applied to lift maximization of a multi-element landing configuration. The governing flow equations are the two-dimensional compressible Navier–Stokes equations in conjunction with a one-equation transport turbulence model. The objective function gradient is computed via the discrete-adjoint method. The design examples reveal a number of difficulties for numerical optimization methods when applied to high-lift design problems, which include flow solver convergence problems at stall and post-stall conditions and poor off-design performance. Strategies are presented for addressing these difficulties, and an example is provided to demonstrate the approach.