AN INSTRUMENT FOR THE SIMULTANEOUS MEASUREMENT OF VELOCITY TEMPERATURE AND DENSITY OF UNSEEDED AIR-FLOWS

WE PROPOSE TO DEVELOP A NEW TECHNIQUE FOR THE MEASUREMENT OF AIR VELOCITY. THE TECHNIQUE WILL USE AN ARF LASER TO FORM CO TRACERS BY DISSOCIATING ATMOSPHERIC CO(2). THE SAME LASER PULSE WILL ALSO BE USED TO INTERROGATE THE TRACERS. WE ARE ALREADY DEVELOPING A LASER-INDUCED FLUORESCENCE TECHNIQUE FOR THE MEASUREMENT OF AIR TEMPERATURE AND DENSITY. WE WILL COMBINE THE TWO SYSTEMS TO FORM A DEVICE FOR SINGLE PULSE MEASUREMENT OF THREE INDEPENDENT FLOW PARAMETERS. THE SYSTEM WILL BE MOST SUITED FOR COLD FLOW HYPERSONIC (3-20 MACHS) WIND TUNNEL APPLICATIONS. IT WILL RELY ON THE SCATTERING FROM NATURAL AIR CONSTITUENTS (N(2), O(2), CO(2)) WITH NO SEEDING REQUIREMENTS AND WITH THE NEED FOR ONLY ONE ACCESS WINDOW. THESE FEATURES MAKE THIS INTEGRATED SYSTEM A CANDIDATE INSTRUMENT FOR BOTH WIND TUNNEL AND ON-FLIGHT MEASUREMENTS.