In this work, using an unified framework consisting in a third-order accurate DG scheme, we perform a comparison between five different numerical approaches to the free-surface flow on bottom steps. We consider three widespread approaches that perform well if the motionless steady state has to be preserved and two approaches (one characterized by a limited diffusion and one original) which are also promising for the preservation of a moving-water steady state. Several one-dimensional test cases are used to verify the third-order accuracy of the models in simulating an unsteady flow, the behavior of the models for a quiescent flow in the cases of both continuous and discontinuous bottom, and the good resolution properties of the schemes. Moreover, a specific test case is introduced to highlight the behavior of the different approaches when a bottom step interact with a steady moving flow.
In this work, using an unified framework consisting in third-order accurate discontinuous Galerkin schemes, we perform a comparison between five different numerical approaches to the free-surface shallow flow simulation on bottom steps.Together with the study of the overall impact that such techniques have on the numerical models we highlight the role that the treatment of bottom discontinuities plays in the preservation of specific asymptotic conditions. In particular, we consider three widespread approaches that perform well if the motionless steady state has to be preserved and two approaches (one previously conceived by the first two authors and one original) which are also promising for the preservation of a moving-water steady state.Several one-dimensional test cases are used to verify the third-order accuracy of the models in simulating an unsteady flow, the behavior of the models for a quiescent flow in the cases of both continuous and discontinuous bottom, and the good resolution properties of the schemes. Moreover, specific test cases are introduced to show the behavior of the different approaches when a bottom step interact with both steady and unsteady moving flows. (C) 2015 Elsevier Inc. All rights reserved.
A comparison between bottom-discontinuity numerical treatments in the DG framework
CALEFFI, Valerio;VALIANI, Alessandro;
2016
Abstract
In this work, using an unified framework consisting in third-order accurate discontinuous Galerkin schemes, we perform a comparison between five different numerical approaches to the free-surface shallow flow simulation on bottom steps.Together with the study of the overall impact that such techniques have on the numerical models we highlight the role that the treatment of bottom discontinuities plays in the preservation of specific asymptotic conditions. In particular, we consider three widespread approaches that perform well if the motionless steady state has to be preserved and two approaches (one previously conceived by the first two authors and one original) which are also promising for the preservation of a moving-water steady state.Several one-dimensional test cases are used to verify the third-order accuracy of the models in simulating an unsteady flow, the behavior of the models for a quiescent flow in the cases of both continuous and discontinuous bottom, and the good resolution properties of the schemes. Moreover, specific test cases are introduced to show the behavior of the different approaches when a bottom step interact with both steady and unsteady moving flows. (C) 2015 Elsevier Inc. All rights reserved.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
