MODELLING OF MASSIVELY SEPARATED FLOWS: RENORMALIZATION GROUP FORMULATION

RECENT DEVELOPMENTS IN HIGH ACCURACY SPECTRAL ELEMENT TECHNOLOGY AND RENORMALIZATION GROUP METHODS AS APPLIED TO TURBULENCE HAVE MADE POSSIBLE DESIGN OF SOFTWARE OF CRITICAL INTEREST TO BOTH GOVERNMENT LABORATORIES AND COMMERCIAL (AEROSPACE) INTERESTS. THE WORK PROPOSED HERE ATTEMPTS TO DESCRIBE THE BEHAVIOR OF MASSIVELY SEPARATED FLOWS USING RNG BASED TURBULENCE MODELS AND SPECTRAL PATCHING ELEMENTS THAT EASILY MODEL COMPLEX GEOMETRIES. EXISTING TURBULENCE TRANSPORT MODELS OFTEN FAIL TO DESCRIBE THE BEHAVIOR OF NON-EQUILIBRIUM TURBULENT FLOWS IN WHICH THERE ARE STRONG DEVIATION FROM THE LAW OF THE WALL. THIS BREAKDOWN MAY BE TRACED TO AN INADEQUATE TREATMENT OF THE INTERACTION BETWEEN EDDY AND MOLECULAR TRANSPORT IN THE WALLLAYERS. RECENTLY, WE HAVE DEVELOPED A NEW METHOD BASED ON RENORMALIZATION GROUP TECHNIQUES THAT HAVE BEEN SHOWN TO PERFORM WELL IN A VARIETY OF SITUATIONS, INCLUDING NON-EQUILIBRIUM FLOWS. THE ORIGIN OF THE SUCCESS OF THESE RNG MODELS IS THE FACT THAT THEY ARE DIFFERENTIAL IN CHARACTER AND NOT BASED ON CLASSICAL AD HOC ALGEBRAIC RELATIONS. PROOF OF VALIDATION STUDIES PROPOSED IN PHASE I (TURBULENT FLOW OVER BACKWARD FACING STEP) COMBINED WITH PHASE II STUDY FOCUSSING ON COMPRESSIBILITY EFFECTS AND COMPLEX GEOMETRY PACKAGE DEVELOPMENT, WILL PROVIDE A MUCH NEEDED PREDICTION SOFTWARE FOR AEROSPACE PROBLEMS.