COMPACT RUGGED LASER DOPPLER VELOCIMETER PROBE FOR IN-FLIGHTGAS TURBINE INLET FLOW MEASUREMENT

MEASUREMENTS OF THE INLET FLOW FIELDS OF AIRCRAFT PROPULSIONSYSTEMS ARE IMPORTANT IN DEFINING THE THRUST AND EFFICIENCY OF THESE ENGINES AS WELL AS IN FLIGHT SAFETY WHEN EXECUTING AVOIDANCE MANEUVERS. THIS PROJECT WILL DEVELOP A NON-INTRUSIVE LASER-DOPPLER VELOCIMETER (LDV) PROBE THAT IS COMPACT AND RUGGED ENOUGH TO PERFORM THESE MEASUREMENTS IN FLIGHT. THIS LDV PROBE WILL REPLACE THE MORE INTRUSIVE AND BULKY MATERIAL PROBES CURRENTLY IN USE. MAPPING THE INLET FLOW VELOCITY WILL ALLOW MORE ACCURATE MEASUREMENT OF IN-FLIGHT THRUST AS WELL AS AID IN THE UNDERSTANDING OF INLET STALL AND SEPARATION. THIS PROBE IS ONLY NOW POSSIBLEWITH RECENT DEVELOPMENTS IN FIBER OPTICS AND FREQUENCY-DOMAIN SIGNAL PROCESSING. THIS PROJECT INVOLVES THE DEFINITION, DESIGN, AND PRELIMINARY TESTING OF AN INNOVATIVE PROBE TO MEASURE THESE INLET FLOW FIELDS. SIZE DISCRIMINATION OF SEEDED PARTICLES WILL BE INCLUDED SO THAT ATMOSPHERIC AEROSOIS CAN BE USED AS SEED PARTICLES. TESTINGOF THE PROTOTYPE PROBE WILL BE CONDUCTED BOTH IN SIMULATED AND GROUND-TETHERED FLOW FIELDS. MEASUREMENTS OF THE INLET FLOW FIELDS OF AIRCRAFT PROPULSIONSYSTEMS ARE IMPORTANT IN DEFINING THE THRUST AND EFFICIENCY OF THESE ENGINES AS WELL AS IN FLIGHT SAFETY WHEN EXECUTING AVOIDANCE MANEUVERS. THIS PROJECT WILL DEVELOP A NON-INTRUSIVE LASER-DOPPLER VELOCIMETER (LDV) PROBE THAT IS COMPACT AND RUGGED ENOUGH TO PERFORM THESE MEASUREMENTS IN FLIGHT. THIS LDV PROBE WILL REPLACE THE MORE INTRUSIVE AND BULKY MATERIAL PROBES CURRENTLY IN USE. MAPPING THE INLET FLOW VELOCITY WILL ALLOW MORE ACCURATE MEASUREMENT OF IN-FLIGHT THRUST AS WELL AS AID IN THE UNDERSTANDING OF INLET STALL AND SEPARATION. THIS PROBE IS ONLY NOW POSSIBLEWITH RECENT DEVELOPMENTS IN FIBER OPTICS AND FREQUENCY-DOMAIN SIGNAL PROCESSING. THIS PROJECT INVOLVES THE DEFINITION, DESIGN, AND PRELIMINARY TESTING OF AN INNOVATIVE PROBE TO MEASURE THESE INLET FLOW FIELDS. SIZE DISCRIMINATION OF SEEDED PARTICLES WILL BE INCLUDED SO THAT ATMOSPHERIC AEROSOIS CAN BE USED AS SEED PARTICLES. TESTINGOF THE PROTOTYPE PROBE WILL BE CONDUCTED BOTH IN SIMULATED AND GROUND-TETHERED FLOW FIELDS.