Improvements in the reliability and quality of unstructured hybrid mesh generation
Improvements in the reliability and quality of unstructured hybrid mesh generation
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DOI：
10.1002/fld.669
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发表时间：
2004-05-10
影响因子：
1.8
通讯作者：
Nakahashi, K
中科院分区：
文献类型：
--
作者：
Ito, Y;Nakahashi, K
本文提出了一种可靠的、自动化的方法来生成由四面体、棱镜和金字塔组成的非结构化混合网格，用于高雷诺数粘性流动模拟。为了增强鲁棒性，混合网格生成过程从各向同性四面体网格的形成开始。然后，通过遵守用户指定的边界条件和三个参数，将棱柱形层完全自动地添加到防滑壁上：层数，与壁面垂直的初始层厚度。还有一个拉伸因子。在层生成过程中，禁止对原始各向同性四面体单元进行拓扑修改。靠近防滑壁的四面体单元向内移动，四面体与壁之间的间隙由棱柱形单元填充。为了提高棱柱层在尖角周围的质量，对这些区域的行进过程进行了两条法线的评估。如果创建了负体积元素或没有留下足够的空间，则局部停止添加棱柱形元素。基于角度的平滑方法在合理的计算成本下保证了四面体单元的质量。该方法在美国国家航空航天研究院设计的两个按比例的实验超音速飞机模型上进行了验证。日本航天实验室（NAL）。数值结果与风洞实验数据进行了比较。版权所有：John Wiley Sons， Ltd. 2004
This paper presents a reliable and automated approach to the generation of unstructured hybrid grids comprised of tetrahedra, prisms and pyramids for high Reynolds number viscous flow simulations. To enhance robustness, the hybrid mesh generation process starts with the formation of an isotropic tetrahedral grid. Prismatic layers are then added on no-slip walls fully automatically by obeying user-specified boundary conditions and three parameters: the number of the layers, an initial layer thickness normal to the walls. and a stretching factor. Topological modifications to the original isotropic tetrahedral elements are prohibited during the layer generation process. The tetrahedral elements near no-slip walls are shifted inward and the resulting gap between the tetrahedra and the walls is filled up with prismatic elements. To enhance the quality of the prismatic layers around sharp corners, two normals are evaluated for the marching process in these regions. The addition of prismatic elements is locally stopped if negative-volume elements are created or not enough space is left. An angle-based smoothing method ensures that the quality of the tetrahedral elements is retained for a reasonable computational cost. The method is demonstrated for two scaled experimental Supersonic airplane models designed at the National. Aerospace Laboratory of Japan (NAL). Numerical results are compared with wind tunnel experimental data. Copyright (C) 2004 John Wiley Sons, Ltd.