“…[30]. There have been several DG methods suggested in literature to solve the problem, including the method originally proposed by Bassi and Rebay [4] for compressible Navier-Stokes equations, its generalization called the local discontinuous Galerkin (LDG) methods introduced in [19] by Cockburn and Shu and further studied in [6,7,12,15]; as well as the method introduced by Baumann-Oden [5,27]. Also in the 1970s, Galerkin methods for elliptic and parabolic problems using discontinuous finite elements, called the interior penalty (IP) methods, were independently introduced and studied; see, e.g., [1,3,34].…”