BOUNDARY LAYER TRANSITION DETECTION SYSTEM

THE OBJECTIVE OF THIS PROJECT IS TO DEVELOP A PROTOTYPE BOUNDARY LAYER TRANSITION DETECTION SYSTEM (BLTDS) THAT INCORPORATES PIEZO-ELECTRIC MATERIAL TO SENSE LAMINAR, TRANSITIONAL, AND TURBULENT BOUNDARY LAYER PRODUCED SIGNALS AND TO DETECT THE POINT OF TRANSITION. A NOVEL CONCEPT CONCEIVED BY THE PROPOSER THAT UTILIZES SOLID-STATE PIEZOELECTRIC SENSOR TECHNOLOGY INDICATES THAT IT IS POSSIBLE TO SENSE BOTH SURFACE DRAG SHEAR FORCE AND ACOUSTICNOISE GENERATED BY THE AIRFLOW. THE KEY ELEMENTS OF THIS SYSTEM UTILIZE POLYVINYLIDENE FLOURIDE TRANSDUCER FILM MATERIAL (PVDF) FOR SENSING AND A MICROCOMPUTER FOR DIGITAL SIGNAL PROCESSING. DUE TO ITS EXCELLENT PIEZOELECTRIC PROPERTIES AND BROADBAND RESPONSE, THE PVDF CAN SENSE THE BOUNDARY LAYER SURFACE VIBRATORY MOTION RESPONDING TO FREQUENCIES FROM A FEW HZ TO 100 KHZ AND HIGHER. BY INCORPORATING A MICROCOMPUTER INTO THIS SYSTEM, A NUMBER OF DESIGN ADVANTAGES IMMEDIATELY BECOME AVAILABLE. IT WILL BE POSSIBLE TO CONSTRUCT A NONINTRUSIVE PROTOTYPE BLTDS THAT DETERMINES LAMINAR, TURBULENT, AND TRANSITIONAL CONDITIONS ON BOTH WIND TUNNEL MODELS AS WELL AS ACTUAL AIRCRAFT FLIGHT CONTROL SURFACES.