Efficient generation of high-quality unstructured surface and volume grids
Efficient generation of high-quality unstructured surface and volume grids
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DOI：
10.1007/pl00013386
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发表时间：
2001-01-01
影响因子：
8.7
通讯作者：
Marcum, DL
中科院分区：
文献类型：
--
作者：
Marcum, DL
提出了有效生成高质量非结构化表面和体积网格的程序。整个过程基于经过充分验证的前进前/本地重连接（AFLR）方法。 AFLR 三角形/四面体网格生成过程是自动点创建、先进型理想点放置和连接优化方案的组合。在整个网格生成过程中维护有效的网格。这提供了一个使用简单数据结构实现高效本地搜索操作的框架。它还提供了一种使用点分布函数在现场平滑分布所需点间距的方法。该函数通过从边界点间距进行插值或通过垂直于边界的指定增长在场中传播。使用各向同性元素的前进前类型点放置、各向同性直角元素的前进点类型点放置或高纵横比元素的前进法线类型点放置来生成点。新点的连通性最初是通过直接细分包含它们的元素来获得的。然后使用具有最小-最大类型（最小化最大角度）类型标准的局部重新连接来优化连接。重复应用整个过程，直到获得完整的场网格。前进法线程序与 AFLR 相结合，用于各向异性四面体和五面体单元网格。从实体边界沿着规定的法线前进会生成各向异性元素层。生成的点使得可以直接恢复具有隐含连通性的五面体或四面体单元。 AFLR 表面网格过程在网格生成过程中使用近似物理空间网格来定义表面。完成后，映射的空间坐标将映射回实际表面。多个表面定义面片被分组为单个表面。使用分组表面连通性为单个表面生成全局映射变换。映射坐标是通过求解一组耦合的拉普拉斯方程获得的。整个过程已应用于多种配置。所提供的选定结果表明，可以为复杂的配置高效且一致地生成高质量的非结构化网格。
Procedures are presented for efficient generation of high-quality unstructured surface and volume grids. The overall procedure is based on the well-proven Advancing-Front/Local-Reconnection (AFLR) method. The AFLR triangular/tetrahedral grid generation procedure is a combination of automatic point creation, advancing type ideal point placement, and connectivity optimization schemes. A valid grid is maintained throughout the grid generation process. This provides a framework for implementing efficient local search operations using a simple data structure. It also provides a means for smoothly distributing the desired point spacing in the field using a point distribution function. This function is propagated through the field by interpolation from the boundary point spacing or by specified growth normal to the boundaries. Points are generated using either advancing-front type point placement for isotropic elements, advancing-point type point placement for isotropic right angle elements, or advancing-normal type point placement for high-aspect-ratio elements. The connectivity for new of the points is initially obtained by direct subdivision of elements that contain them. Local-reconnection with a min-max type (minimize the maximum angle) type criterion is then used to optimize the connectivity. The overall procedure is applied repetitively until a complete field grid is obtained. An advancing-normal procedure is coupled with AFLR for anisotropic tetrahedral and pentahedral element grids. Advancing along prescribed normals from solid boundaries generates layers of anisotropic elements. The points are generated such that either pentahedral or tetrahedral elements with an implied connectivity can be directly recovered. The AFLR surface grid procedure uses an approximate physical space grid to define the surface during grid generation. The mapped space coordinates are mapped back to the actual surface at completion. Multiple surface definition patches are grouped into a single surface. A global mapping transformation is generated for the single surface using the grouped surface connectivity. The mapping coordinates are obtained by solving a coupled set of Laplacian equations. The overall procedure has been applied to a wide variety of configurations. Selected results are presented which demonstrate that high-quality unstructured grids can be efficiently and consistently generated for complex configurations.