A UNIFIED CONSERVATIVE INTERFACE TREATMENT FOR ARBITRARILY OVERSET AND PATCHED MULTI-ZONE GRIDS IN COMPUTATIONAL FLUID DYNAMICS

IN THE FIELD OF COMPUTATIONAL FLUID DYNAMICS (CFD), A MULTIZONAL APPROACH GREATLY SIMPLIFIES THE RESOLUTION OF COMPLEX GEOMETRICAL DETAILS AND THE APPLICATION OF DIFFERENT FLOW PHYSICS IN DIFFERENT ZONES OF THE FLOW DOMAIN. PREVIOUS MULTI-ZONAL PATCHED AND OVERLAPPED APPROACHES SUFFERED FROM ONE OR BOTH OF THE FOLLOWING PROBLEMS: CONSERVATION AND GENERALITY. A NEW APPROACH TO RESOLVE BOTH OF THESE PROBLEMS IS TO USE ONE OF THE OVERLAPPING BOUNDARIES TO DIVIDE THE PHYSICAL FLOW DOMAIN INTO NON-OVERLAPPING REGIONS AND ENFORCING FLUX CONSERVATION ON THIS OVERLAPPING BOUNDARY LOCALLY AND GLOBALLY. THE APPROACH UNIFIES THE TREATMENT FOR ARBITRARILY PATCHED AND OVERLAPPED MESHES. THE INTERPOLATION OF FLOW VARIABLES FROM ONE ZONE TO ANOTHER IS NOT NECESSARY. THE APPROACH IS FULLY CONSERVATIVE, HIGHLY ACCURATE, SUITABLE FOR BOTH STEADY AND UNSTEADY FLOW PROBLEMS, AND EASY TO IMPLEMENT IN FINITE-DIFFERENCE/FINITE VOLUME CFD CODES. THE METHODOLOGY IS BEING IMPLEMENTED AND ASSESSED FOR SEVERAL 2D AND 3D PROBLEMS WITHOUT RELATIVE MESH MOVEMENT.