INNOVATIVE BOUNDARY LAYER CONTROL METHODS IN HIGH SPEED INLET SYSTEMS

A PROGRAM OF RESEARCH IS PROPOSED THAT WILL REVIEW THE RELEVANT LITERATURE ON RECENT DEVELOPMENTS IN BOUNDARY LAYERCONTROL IN HIGH-SPEED ENGINE INLETS. OF PARTICULAR INTERESTWILL BE INLETS INTENDED TO OPERATE AT FLIGHT MACH NUMBERS ABOVE 3.0 WHERE VISCOUS EFFECTS DOMINATE THE BEHAVIOR OF THEINTERNAL FLOW. THE OBJECTIVE OF THE PHASE I EFFORT IS TO DETERMINE THE FEASIBILITY OF USING INNOVATIVE BOUNDARY LAYERCONTROL ARRANGEMENTS THAT ALLOW HIGH INLET RECOVERY TO BE ACHIEVED AT LOW BLEED RATES. THE INVESTIGATION IS AN ANALYTIC ONE AND WILL BE CARRIED OUT WITH THE USE OF A FULL NAVIER-STOKES CODE. OF PARTICULAR INTEREST ARE CALCULATIONSTHAT WILL ADDRESS THE CONTROL OF THE STRONG LATERAL FLOW COMPONENT KNOWN TO EXIST IN GLANCING (OR SIDEWALL) SHOCK WAVE/BOUNDARY LAYER INTERACTIONS TYPICAL OF THOSE OCCURRING IN HIGH-SPEED ENGINE INLETS. AN EXAMPLE OF THE PROPOSED NAVIER-STOKES CODE APPLIED TO A MACH 5 INLET WITH BOUNDARY LAYER BLEED IS SHOWN AND EXTENSIONS OF THIS WORK ARE PROPOSED TO INCLUDE PARAMETRIC AND NOVEL INVESTIGATIONS OF DIFFERENT BOUNDARY LAYER BLEED ARRANGEMENTS. EFFORT PROPOSED FOR PHASE I WILL FOCUS ON OPTIMIZATION OF BLEED FOR BOUNDARY LAYER CONTROL WITHIN THE SUPERSONIC PORTION OF THE INLET ONLY. THE PROPOSED WORK IS TO BE CARRIED OUT ON THE NASA NATIONAL AERODYNAMIC SIMULATION FACILITY.