{ "id": "1912.09577", "version": "v1", "published": "2019-12-19T22:20:21.000Z", "updated": "2019-12-19T22:20:21.000Z", "title": "An all speed second order well-balanced IMEX relaxation scheme for the Euler equations with gravity", "authors": [ "Andrea Thomann", "Gabriella Puppo", "Christian Klingenberg" ], "categories": [ "math.NA", "cs.NA" ], "abstract": "We present an implicit-explicit well-balanced finite volume scheme for the Euler equations with a gravitational source term which is able to deal also with low Mach flows. To visualize the different scales we use the non-dimensionalized equations on which we apply a pressure splitting and a Suliciu relaxation. On the resulting model, we apply a splitting of the flux into a linear implicit and an non-linear explicit part that leads to a scale independent time-step. The explicit step consists of a Godunov type method based on an approximative Riemann solver where the source term is included in the flux formulation. We develop the method for a first order scheme and give an extension to second order. Both schemes are designed to be well-balanced, preserve the positivity of density and internal energy and have a scale independent diffusion. We give the low Mach limit equations for well-prepared data and show that the scheme is asymptotic preserving. These properties are numerically validated by various test cases.", "revisions": [ { "version": "v1", "updated": "2019-12-19T22:20:21.000Z" } ], "analyses": { "keywords": [ "second order well-balanced imex relaxation", "order well-balanced imex relaxation scheme", "speed second order well-balanced imex", "euler equations", "well-balanced finite volume scheme" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }