High-Density Mesh Flow Computations with Pre-/Post-Data Compressions
High-Density Mesh Flow Computations with Pre-/Post-Data Compressions
复制标题
具有前/后数据压缩的高密度网格流计算
DOI：
10.2514/6.2005-4876
复制
发表时间：
2005
期刊：
影响因子：
2.5
通讯作者：
K. Nakahashi
中科院分区：
文献类型：
--
作者：
K. Nakahashi
本文在建筑立方体方法(BCM)的框架内讨论了大规模流动计算前后文件的数据压缩，该方法是针对真实几何的域名系统而提出的，以期在不久的将来实现高性能计算机。在BCM中，一个流场被描述为长方体的积木的集合，被称为‘立方体’。每个立方体都是流计算的一个子域，其中使用了等间距的笛卡尔网格。所有立方体具有相同数量的网格点，每个立方体的几何尺寸通过适应几何和流动特征来确定，以使网格间距与局部流动尺度相适应。网格数据使用游程技术进行压缩，结合立方体框架和对墙边界的简单处理。采用一种类似于图像数据压缩的矢量量化方法来压缩非定常流动每个时间帧的解数据。将本方法应用于两个翼型，其结果揭示了边界层中详细的旋涡运动，并表明在边界层中使用各向同性、高密度网格的重要性。
In this paper, data compressions of pre-/post-files of large-scale flow computations are discussed within a framework of the Building-Cube Method (BCM), that was proposed aimed for DNS around real geometries with an expectation of near-future high-performance computers. In the BCM, a flow field is described as an assemblage of building blocks of cuboids, named ‘Cube’. Each cube is a sub-domain of the flow computation and an equallyspaced Cartesian mesh is used in it. All cubes have the same number of grid points and the geometrical size of each cube is determined by adapting to the geometry and the flow features so as to fit the grid spacing to the local flow scale. The grid data are compressed using the run-length technique, combined with the cube framework and the simple treatment of the wall boundaries. The solution data of each time frame of an unsteady flow are compressed by a technique similar to the vector quantization method proposed for image-data compressions. The present method is applied to two airfoils whose results reveal the detailed vortex motions in the boundary layers and shows the importance to use the isotropic, high-density mesh in the boundary layer.