ADAPTIVITY FOR COMPRESSIBLE FLOW COMPUTATIONS USING POINT EMBEDDING ON 2-D STRUCTURED MULTIBLOCK MESHES

Structured meshes which consist of a single curvilinear network of lines and points have limited flexibility when applied to geometrically complicated domains. To alleviate this constraint the idea of multiblock structured meshes has been proposed. This approach subdivides the domain of interest into regions, each of which can be mapped into a transformed space equivalent to a rectangle. The connections between these regions define the mesh topology. By a suitable subdivision of the domain, multiblock grids, which are globally unstructured between blocks, but provide a structured grid within blocks, can be used to discretize highly complex geometrical domains. This technique has been used to great effect, both in two and three dimensions. However, structured meshes are not naturally amenable to adaptivity techniques based upon local point addition. This paper describes a method, based upon the quadtree data structure, which allows for local point refinement on multiblock meshes for use with flow algorithms for the simulation of compressible flow around aerospace geometries. The basic concepts of multiblock meshes, the use of the quadtree data structure, together with the treatment within the flow algorithm of locally embedded meshes, will be discussed.