Application #44. Adjoint-Based Adaptation Applied to Supersonic Double-Airfoil

Contributed by David Venditti and David Darmofal, MIT

Comparison of traditional feature-based adaptation with adjoint-based adaptation for Mach 3 flow over a pair of airfoils.

The objective is to predict drag on the lower airfoil as accurately as possible. The feature-based method refines all of the complicated shock structures to compute a drag of 767 counts on 37,352 grid points. The adjoint method determines that the shock patterns are largely unimportant for the lower airfoil drag and does not resolve them. The adjoint approach gives essentially the same answer (766 counts) by using a grid composed of only 3,810 grid points—one-tenth of that required by the feature-based scheme.