LASER DOPPLER VELOCIMETER FOR FLOW RATE MEASUREMENT IN CONTROL FLUID SYSTEMS

A NON-INTRUSIVE FLOW MEASUREMENT SYSTEM IS PROPOSED FOR SMALL DIAMETER, LOW FLOW RATE, AND LOW PRESSURE DIFFERENTIALTHERMAL CONTROL FLUID SYSTEMS. THE PROPOSED TECHNIQUE UTILIZES A CW DIODE BASED LASER DOPPLER VELOCIMETER (LDV) WHICH CAPTURES SCATTERED RADIATIONFROM MINUTE (<10.0 UM) INERT PARTICLES SUSPENDED IN THE FLOWMEDIUM. THE PARTICULATES MAY OCCUR NATURALLY AS IMPURITIES IN THE COOLANT OR MAY BE MIXED IN THE COOLANT AT THE TIME OFA SYSTEM FILL. WITH THIS TECHNIQUE AN ACCURATE GROUND CHECK SYSTEM CAN BE DEVELOPED TO ASSURE PROPER FUNCTION OF INTERDEPENDENT THERMAL CONTROL SYSTEMS. THEORETICAL CALCULATIONS INDICATE THAT THE SYSTEM WILL PROVIDE FLOW MEASUREMENT CAPABILITIES AT FLOW RATES AS LOW AS 10.0 LBS/HR FOR FREON-12 AND DEIONIZED WATER COOLING SYSTEMS IN PIPE DIAMETERS OF 1/8 TO 1/2 INCH WITH ACCURACIESOF 0.5% OR BETTER. PHASE I RESEARCH WILL CONSIST OF THE DESIGN AND CONSTRUCTIONOF A PROOF-OF-CONCEPT PROTOTYPE AND EXPERIMENTAL VERIFICATION OF SYSTEM CAPABILITIES.