Aerodynamic Optimization of Turbine Airfoils Using Multi-fidelity Surrogate Models

Abstract

For many applications numerical simulations are available in varying degrees of fidelity and computational expense. On the one hand, in an accurate and time-consuming high-fidelity (HiFi) version, that is used as a reference for design and optimization, and on the other hand, in a low-fidelity (LoFi) version that is faster but less accurate. In computational fluid dynamics (CFD) of turbine airfoils an accurate 3D solver accounts for the HiFi model and a faster 2D solver for the LoFi model. Assuming the LoFi model captures the fundamental physics reasonably well, many inexpensive LoFi computations may be coupled with a few expensive HiFi computations to enhance the accuracy of a surrogate model based solely on the HiFi data. In this way multi-fidelity surrogate models can be used to speed up the optimization.