Abstract As an efficient simulation method for complex configurations and moving boundary problems in computational fluid dynamics, Chimera or overset grid techniques have been widely used in many aspects of aeronautics and astronautics. However, there are still some bottlenecks for the current hole-cutting method to handle large scale mesh, such as memory storage limitation and parallel efficiency. In this paper, a parallel implicit hole-cutting method based on unstructured background mesh is presented. The method is based on the parallel searching of donor cells for all grid nodes. In order to reduce the memory consumption of the searching procedure for the large-scale grids, a global-to-local (GTL) searching strategy as well as the background grid approach is developed. To improve the connectivity of overset domains, a parallel front advancing method is adopted to automatically distinguish the active regions. Finally, the efficiency and effectiveness of the present Chimera grid method are validated by some test cases and applications, including multi-store separation from a fighter and a missile pitching-up maneuvering with rudder deflection under a control command. The numerical results demonstrate the potential for steady and unsteady CFD simulations for complex geometries.

中文翻译：

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一种基于背景网格的非结构化嵌合体网格平行隐式切孔方法

摘要 作为计算流体动力学中复杂构型和移动边界问题的一种有效模拟方法，Chimera或重叠网格技术已广泛应用于航空航天的许多方面。然而，当前的切孔方法处理大规模网格仍然存在一些瓶颈，例如内存存储限制和并行效率。本文提出了一种基于非结构化背景网格的并行隐式切孔方法。该方法基于对所有网格节点的供体单元的并行搜索。为了减少大规模网格搜索过程的内存消耗，开发了一种全局到局部（GTL）搜索策略以及背景网格方法。为了改善重叠域的连通性，采用平行前沿推进方法自动区分活动区域。最后，通过一些测试案例和应用验证了当前 Chimera 网格方法的效率和有效性，包括与战斗机的多存储分离和在控制命令下带有方向舵偏转的导弹俯仰机动。数值结果证明了复杂几何形状的稳态和非稳态 CFD 模拟的潜力。