Anisotropic adaptation of moving unstructured mesh to bodies of complex shapes described by an interpolation octree

A methodology for anisotropic adaptation of a moving unstructured mesh to the surface of an object of arbitrary shape with account for its possible displacement is proposed. The mesh adaptation is developed in order to use the adapted mesh in problems of external flow in which the bodies in airflow are modeled as regions in a continuous medium with low permeability using the immersed boundary method. This approach gives a problem in a simply connected domain and makes it possible to use the technique of mesh node redistribution that preserves the topology of the original mesh for dynamic adaptation. The main input adaptation parameter is the distance function to the body surface, and its anisotropic nature is determined by the calculated curvature fields associated with the body geometry. All adaptation parameters are specified at the nodes of a preliminary constructed octree, which is the body attribute and describes its geometry. A detailed description of the anisotropic adaptation is given and examples of its application are discussed.