Entropy and Adjoint Methods

Autor: Lozano, Carlos
Rok vydání: 2023
Předmět:
Zdroj: J Sci Comput 81 (2019) 2447-2483
Druh dokumentu: Working Paper
DOI: 10.1007/s10915-019-01092-0
Popis: Aerodynamic drag can be partially approximated by the entropy flux across fluid domain boundaries with a formula due to Oswatitsch. In this paper, we build the adjoint solution that corresponds to this representation of the drag and investigate its relation to the entropy variables, which are linked to the integrated residual of the entropy transport equation. For inviscid isentropic flows, the resulting adjoint variables are identical to the entropy variables, an observation originally due to Fidkowski and Roe, while for non-isentropic flows there is a significant difference that is explicitly demonstrated with analytic solutions in the shocked quasi-1D case. Both approaches are also investigated for viscous and inviscid flows in two and three dimensions, where the adjoint equations and boundary conditions are derived. The application of both approaches to mesh adaptation is investigated, with especial emphasis on inviscid flows with shocks.
Comment: This is a postprint (accepted version) of an article published in the Journal of Scientific Computing. The published version may differ from this postprint and is available at: Lozano, C. "Entropy and Adjoint Methods". J Sci Comput (2019). https://doi.org/10.1007/s10915-019-01092-0
Databáze: arXiv