NUMERICAL INVESTIGATION OF UNSTEADY THREE-DIMENSIONAL TURBULENT STRUCTDURES IN BOUNDARY LAYER FLOWS OVER AN AIRFOIL

A PROPOSAL IS PRESENTED HEREIN TO NUMERICALLY INVESTIGATE THE UNSTEADY DYNAMICS OF HAIRPIN VORTICS SUBMERGED IN VARIOUS BACKGROUND FLOWS. THE COMPUTER CODE TO BE USED WAS DEVELOPED FOR CALCULATING UNSTEADY THREE-DIMENSIONAL TURBULENT BOUNDARY LAYER FLOWS ON WINGS AND IS CAPABLE OF TREATING NEGATIVE CROSS FLOW AND STREAMWISE REVERSE FLOW. UNDER PHASE I OF THE CURRENT PROPOSAL, THE BACKGROUND FLOW WOULD BE THE MEAN TURBULENT FLOW FIELD OVER A NEWMAN AIRFOIL AND TWO SETS OF PROBLEMS WOULD BE CONSIDERED. THE FIRST ONE WOULD BE THE STUDY OF THE BEHAVIOR OF ISOLATED HAIRPIN VORTEX OF DIFFERENT LENGTH SCALE IN THE GIVEN BACKGROUND FIELD. THE SECOND SET WOULD BE THE INVESTIGATION OF THE EFFECTS OF UNSTEADY VORTEX GENERATION ON THE TURBULENCE CHARACTERISTICS OF THE NEWMAN AIRFOIL FLOW.