An optimal order interior penalty discontinuous Galerkin discretization of the compressible Navier-Stokes equations

In this article we propose a new symmetric version of the interior penalty dis-continuous Galerkin nite element method for the numerical approximation of the compressible Navier-Stokes equations. Here, particular emphasis is devoted to the construction of an optimal numerical method for the evaluation of certain target functionals of practical interest, such as the lift and drag coecients of a body im-mersed in a viscous uid. With this in mind, the key ingredients in the construction of the method include: (i) An adjoint consistent imposition of the boundary con-ditions; (ii) An adjoint consistent reformulation of the underlying target functional of practical interest; (iii) Design of appropriate interior{penalty stabilization terms. Numerical experiments presented within this article clearly indicate the optimality of the proposed method when the error is measured in terms of both the L2-norm, as well as for certain target functionals. Computational comparisons with other discon-tinuous Galerkin schemes proposed in the literature, including the second scheme of Bassi & Rebay, cf. [12,13], the standard SIPG method outlined in [27], and an NIPG variant of the new scheme will be undertaken