Adjoint-based adaptive mesh refinement for sonic boom prediction

Abstract

Output-driven mesh adaptation is used in conjunction with an embedded-boundary Cartesian meshing scheme for sonic-boom simulations. The approach automatically re-fines the volume mesh in order to minimize discretization errors in output functionals, specifically pressure signals, defined at locations several body-lengths away from the sur-face geometry. Techniques and strategies used to improve accuracy of the propagated signal while decreasing mesh densities are described. The effectiveness of this approach is demonstrated in three dimensions using axisymmetric bodies, a lifting wing-body configu-ration, and the F-5E and Shaped Sonic Boom Demonstration aircraft. Results are validated with available experimental data and indicate that with this approach, accurate pressure signatures can be produced for three-dimensional geometry in just over an hour using a conventional desktop PC. I