关键词: 重叠网格, 割补法, 洞映射, 非结构网格, 物面距离

Abstract: To solve the problem that the hole mapping method occupies too much physical memory, an improved hole mapping method was developed. Based on the neighbor-to-neighbor search algorithm, a donor search method based on adjacent front was developed. An explicit assembly algorithm of unstructured overset grid was presented by combining the cut-paste method with the implicit cutting technique. First, the algorithm generated a set of Cartesian grids surrounding the wall surface. Second, those Cartesian cells intersecting the wall surface were stored. Finally, relative positions of the stored Cartesian cells were used to determine whether a grid point was inside the wall. After successfully determining all the grid points inside the wall, the current fringe grid points were used as the initial front, and the overlapping area was optimized by the wall distance of each grid point to generate the final interpolation boundary. The proposed explicit algorithm optimizes the traditional implicit assembly process of unstructured overset grid. It features in low physical memory occupation, low cost of donor searching and high computational efficiency. The accuracy and applicability of the proposed explicit method were verified by two typical complex flow examples.

Key words: overset grid, cut-paste method, hole mapping, unstructured grid, wall distance