High-order Discontinuous Galerkin solver based on Jacobi polynomial expansion for compressible flows on unstructured meshes

Fuente: arXiv
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Main Authors: Peng, Yu-Xiang, Wang, Biao, Sun, Peng-Nan, Zhang, A-Man
Format: Preprint
Published: 2024
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author Peng, Yu-Xiang
Wang, Biao
Sun, Peng-Nan
Zhang, A-Man
author_facet Peng, Yu-Xiang
Wang, Biao
Sun, Peng-Nan
Zhang, A-Man
contents Based on the Jacobi polynomial expansion, an arbitrary high-order Discontinuous Galerkin solver for compressible flows on unstructured meshes is proposed in the present work. First, we construct orthogonal polynomials for 2D and 3D isoparametric elements using the 1D Jacobi polynomials. We perform modal expansions of the state variables using the orthogonal polynomials, enabling arbitrary high-order spatial discretization of these variables. Subsequently, the discrete governing equations are derived by considering the orthogonality of the Euler equations' residuals and the test functions. On this basis, we develop a high-order Discontinuous Galerkin solver that supports various element types, including triangles, quadrilaterals, tetrahedra, hexahedra, etc. An improved shock-capturing scheme has been adopted to capture shock discontinuities within the flow field. The variable's gradients at the discontinuous elements are reconstructed by its adjacent elements, and the slope limiter is applied to modify the state variables, smoothing the state variables and enhancing the robustness of the solver. The convergence rates of solvers of different orders have been verified by a benchmark case, and the CPU costs are given to prove that high-precision algorithms have higher computational efficiency under the same error level. Finally, several two- and three-dimensional compressible fluid dynamics problems are studied, compared with literature and experimental results, the effectiveness and accuracy of the solver were verified.
format Preprint
id arxiv_https___arxiv_org_abs_2411_15699
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publishDate 2024
record_format arxiv
spellingShingle High-order Discontinuous Galerkin solver based on Jacobi polynomial expansion for compressible flows on unstructured meshes
Peng, Yu-Xiang
Wang, Biao
Sun, Peng-Nan
Zhang, A-Man
Computational Physics
Fluid Dynamics
Based on the Jacobi polynomial expansion, an arbitrary high-order Discontinuous Galerkin solver for compressible flows on unstructured meshes is proposed in the present work. First, we construct orthogonal polynomials for 2D and 3D isoparametric elements using the 1D Jacobi polynomials. We perform modal expansions of the state variables using the orthogonal polynomials, enabling arbitrary high-order spatial discretization of these variables. Subsequently, the discrete governing equations are derived by considering the orthogonality of the Euler equations' residuals and the test functions. On this basis, we develop a high-order Discontinuous Galerkin solver that supports various element types, including triangles, quadrilaterals, tetrahedra, hexahedra, etc. An improved shock-capturing scheme has been adopted to capture shock discontinuities within the flow field. The variable's gradients at the discontinuous elements are reconstructed by its adjacent elements, and the slope limiter is applied to modify the state variables, smoothing the state variables and enhancing the robustness of the solver. The convergence rates of solvers of different orders have been verified by a benchmark case, and the CPU costs are given to prove that high-precision algorithms have higher computational efficiency under the same error level. Finally, several two- and three-dimensional compressible fluid dynamics problems are studied, compared with literature and experimental results, the effectiveness and accuracy of the solver were verified.
title High-order Discontinuous Galerkin solver based on Jacobi polynomial expansion for compressible flows on unstructured meshes
topic Computational Physics
Fluid Dynamics
url https://arxiv.org/abs/2411.15699