Unstructured 2D grid generation using overset-mesh cutting and single-mesh reconstruction

In this paper a new approach for merging overlapping grids for CFD simulations is presented. The proposed strategy is a preprocessor that integrates the overset meshes into a single mesh suitable for unstructured finite volume vertex-centered Navier-Stokes solvers. This strategy aims to deal with complex industrial problems, specially in case of moving components and overlapping boundary layers. The algorithm consists of two key steps: the definition of a hole cutting area over each component mesh, where nodes of the other mesh are removed, and the subsequent remeshing of the gap generated between both meshes. In this process, the first issue is particularly critical and it employs auxiliary coarse Cartesian meshes to simplify the involved computations like wall distance calculations or point inclusion test. The proposed approach has been demonstrated on 2D test configurations using the DLR-TAU solver