LEAKAGE EFFECTS DEVELOPMENT

THE PROPOSED EFFORT WOULD DEVELOP AN ANALYSIS FOR THREE-DIMENSIONAL COMPRESSOR PASSAGE FLOW FIELDS INCLUDING TIP LEAKAGE EFFECTS. THE ANALYSIS WOULD BE BASED UPON A HIGH RESOLUTION, THREE-DIMENSIONAL NAVIER-STOKES APPROACH AND WOULD INCLUDE THE EFFECTS OF BLADE AND CASING BOUNDARY LAYERS, PASSAGE SECONDARY FLOW AND TIP CLEARANCE. AT PRESENT, CASCADE TIP FLOW ANALYSES ARE EITHER SEMI-EMPIRICAL OR BASED UPON SETS OF SIMPLIFIED EQUATIONS WHICH NEGLECT SIGNIFICANT PHYSICAL PHENOMENA. THE PROPOSED EFFORT WOULD BE BASED UPON A HIGHLY RESOLVED NUMERICAL SIMULATION USING THE THREE-DIMENSIONAL NAVIER-STOKES EQUATIONS. THIS APPROACH WOULD ALLOW INCLUSION OF THE RELEVANT PHYSICAL PHENOMENA, WOULD BE AN ECONOMICAL AND EFFICIENT METHOD OF ASSESSING FLOW FIELDS, AND WOULD GIVE DETAILED FLOW FIELD DESCRIPTIONS. UNDER THE PHASE I EFFORT, A GENERAL THREE-DIMENSIONAL NAVIER-STOKES CODE WOULD BE APPLIED TO THE TIP FLOW FIELD PROBLEM. A DEMONSTRATION CALCULATION WOULD BE MADE AND INTERROGATE TO ASSESS THE VIABILITY OF THIS APPROACH. FUTURE EFFECTS WOULD ADD FURTHER GEOMETRIC GENERALITY, PERFORM A QUANTITATIVE ASSESSMENT AND DEVELOP A USER-ORIENTED VERSION OF THE CODE.