Validation of new CFD Tool Using Non-orthogonal Octree with Boundary-fitted Layer Unstructured Grid

This paper describes an introduction and validation results of a newly developed CFD tool, named “Cflow”, which consists of an automatic Cartesian based grid generator and a flow solver based on unstructured finite volume method for polyhedral element grid cells. To allow both automatic grid generation for highly complicated configurations and greater flexibility for high aspect ratio and sweptback wing configurations, Cflow employs “NOBLU (Non-orthogonal Octree with Boundary-fitted Layer Unstructured) Grid.” The grid generator of Cflow also equips feature lines preserving technique. The validation study of Cflow with NOBLU grid for high Reynolds number external flow over the ONERA M6 wing was conducted and showed good agreements with the experimental data. In addition, Cflow is applied to the NASA Common Research Model wing-body configuration. Cflow with NOBLU grid can generate a fair computational grid for such a high aspect ratio aircraft configuration and NOBLU grid proves the superiority over Cartesian based grid.