Approximation and Model Management in Aerodynamic Optimization with Variable-Fidelity Models

This work discusses an approach, Ž rst-order approximation andmodelmanagement optimization (AMMO), for solving design optimization problems that involve computationally expensive simulations. AMMO maximizes the use of lower-Ž delity, cheaper models in iterative procedures with occasional, but systematic, recourse to higherŽ delity, more expensive models for monitoring the progress of design optimization. A distinctive feature of the approach is that it is globally convergent to a solution of the original, high-Ž delity problem. Variants of AMMObased on three nonlinear programming algorithms are demonstrated on a three-dimensional aerodynamic wing optimization problemand a two-dimensional airfoil optimization problem. Euler analysis onmeshes of varying degrees of reŽ nement provides a suite of variable-Ž delity models. Preliminary results indicate threefold savings in terms of high-Ž delity analyses for the three-dimensional problem and twofold savings for the two-dimensional problem.