Surrogate-based Airfoil Design with Space Mapping and Adjoint Sensitivity

• Published in: Procedia computer science 2015, Vol.51, p.795-804
• Main Authors: Tesfahunegn, Yonatan A., Koziel, Slawomir, Leifsson, Leifur, Bekasiewicz, Adrian
• Format: Article
• Language: English
• Subjects: adjoint sensitivity; Aerodynamic shape optimization; multi-fidelity models; space mapping; surrogate-based modeling
• ISSN: 1877-0509; 1877-0509
• DOI: 10.1016/j.procs.2015.05.201

This paper presents a space mapping algorithm for airfoil shape optimization enhanced with adjoint sensitivities. The surrogate-based algorithm utilizes low-cost derivative information obtained through adjoint sensitivities to improve the space mapping matching between a high-fidelity airfoil model, evaluated through expensive CFD simulations, and its fast surrogate. Here, the airfoil surrogate model is constructed though low-fidelity CFD simulations. As a result, the design process can be performed at a low computational cost in terms of the number of high-fidelity CFD simulations. The adjoint sensitivities are also exploited to speed up the surrogate optimization process. Our method is applied to a constrained drag minimization problem in two-dimensional inviscid transonic flow. The problem is solved for several low-fidelity model termination criteria. The results show that when compared with direct gradient-based optimization with adjoint sensitivities, the proposed approach requires 49-78% less computational cost while still obtaining a comparable airfoil design.