非结构变形网格和离散几何守恒律

doi:10.7527/S1000-6893.2016.0141

Abstract

Abstract:

A popular method for simulating unsteady flow of fluid-structure interaction or multi-body separation is finite volume method based on arbitrary Lagrangian-Eulerian (ALE) equations, which involves mesh deformation and discrete geometric conservation law. The fundamental principle, state of the art and boundaries of validity of mesh deformation are reviewed following 5 categories of constructing ideas, e.g., physics analogy, ellipse smoothing, interpolation, moving submesh approach (MSA) and hybrid method. A hybrid method which combines the benefits of MSA and radial basis functions (RBFs) interpolation is proved to be robust and efficient via several numerical examples. After the concept of discrete geometric conservation law (DGCL) is introduced, the intrinsic mechanism of DGCL is analyzed through 2D model, which is the inequality between volume increment and the volume sweeping by the surfaces enclosing of mesh cell. The different implementations of DGCL which could be mainly categorized as area correction, area correction via assuming velocity of surface, velocity correction and volume correction are surveyed and their range of application and the existing problems are discussed. We found that the proposed volume correction method can satisfy the fluid-structure interface condition, and is also appropriate for multi-step temporal discrete schemes.

Key words: unstructured mesh, mesh deformation, unsteady flow, geometric conservation law, interface coupling

CLC Number:

V211.3

LIU Jun, LIU Yu, CHEN Zedong. Unstructured deforming mesh and discrete geometric conservation law[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2016, 37(8): 2395-2407.

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Unstructured deforming mesh and discrete geometric conservation law

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