A survey of overset domain assembly methods

Overset or Chimera grid methods are widely used in industry and academia to solve problems with bodies in relative motion or complex geometry that would otherwise be challenging or even impossible due to the impediments imposed by a single grid representation. These methods utilize a composite mesh to span the computational domain. The composite mesh consists of an arbitrary number of overlapping component meshes. Because the component meshes overlap, inter-grid boundaries must be defined and interpolation stencils must be provided to the flow solver by an overset domain assembly code. The process of defining inter-grid boundaries is often referred to as "hole cutting" because pieces of the component meshes are removed from the computational domain. Hole cutting is computationally expensive and has proven difficult to efficiently parallelize. In order to address this difficulty, the sources of computational cost and those that impede scalability must be identified. This work presents the major sources of computational cost and summarizes current techniques used in their mitigation.