Shifted boundary polynomial corrections for compressible flows: high order on curved domains using linear meshes

Abstract

In this work we propose a simple but effective high order polynomial correction allowing to enhance the consistencyof all kind of boundary conditions for the Euler equations (Dirichlet, characteristic far-field and slip-wall), both in 2Dand 3D, preserving a high order of accuracy without the need of curved meshes. The method proposed is a simplifiedreformulation of the Shifted Boundary Method (SBM) and relies on acorrectionbased on theextrapolated valueof the in cell polynomialto the true geometry, thus not requiring the explicit evaluation of high order Taylor series.Moreover, this strategy could be easily implemented into any already existing finite element and finite volume code.Several validation tests are presented to prove the convergence properties up to order four for 2D and 3D simulationswith curved boundaries, as well as an effective extension to flows with shocks