MULTILEVEL ADAPTIVE METHODS FOR THE EAGLE CODE

THE EAGLE GRID GENERATION CODE IS A WIDELY USED SOFTWARE TOOL FOR GENERATING COMPUTATIONALLY UNIFORM GRIDS THAT FIT IRREGULAR PHYSICAL DOMAINS. BASED ON ELLIPTIC GRID GENERATION, IT USES A BLOCKSTRUCTURED APPROACH TO ACCOMMODATE VERY IRREGULAR REGIONS AND POINT DISTRIBUTION FUNCTIONS TO REDUCE FLOW-SOLVER TRUNCATION ERROR. IT ALSO INCORPORATES AS EULER SOLVER FOR INVISCID FLOW CALCULATIONS. WHILE THE EAGLE CODE HAS SUBSTANTIALLY IMPROVED COMPUTATIONAL CAPABILITIES, THERE ARE SEVERAL OF ITS FEATURES THAT COULD BE DRAMATICALLY IMPROVED BY INCORPORATING MULTILEVEL SOLUTION TECHNIQUES.FIRST, MULTIGRID SOLVRS FOR THE CURRENT GLOBAL GRID EQUATIONS WOULD SHARPLY IMPROVE GRID SMOOTHNESS AND GRID/FLOW SOLVER PERFORMANCE. SECOND, MULTILEVEL ADAPTIVE SCHEMES WOULD PROVIDE THE ABILITY TO EFFICIENTLY GENERATE REFINED BUT SMOOTH LOCAL PATCHES FOR INCREASING RESOLUTION AND ACCURACY AT BODY SURFACES, SINGULAR AND STAGNATION POINTS, SHOCKS, AND OTHER PHENOMENA. FINALLY, THE MULTILEVEL ADAPTIVE METHODS WOULD IMPROVE THE FLOW SIMULATION BY ALLOWING BETTER LOCAL FLOW MODELS IN ADDITION TO HIGHER RESOLUTION. IN PARTICULAR, THE FULL NAVIER-STOKES EQUATIONS COULD BE USED TO INCLUDE VISCOUS EFFECTS IN SPECIAL AREAS OF INTEREST (E.G., BOUNDARY LAYERS). SUCH LOCAL MODELS WOULD COME AT LITTLE ADDITIONAL COST YET WOULD PROVIDE INCREASED ACCURACY THROUGHOUT THE DOMAIN. THE PROJECT OBJECTIVES ARE TO IMPLEMENT THESE MULTILEVEL ENHANCEMENTS TO THE EAGLE CODE.