HYBRID MEASUREMENT OF TWO-PHASE FLOWS

THE ABILITY TO MEASURE THE SIMULTANEOUS LIQUID AND VAPOR FLOW RATES OCCURRING AT VARIOUS POINTS IN A TWO-PHASE THERMAL MANAGEMENT SYSTEM WOULD PROVIDE THE MOST DIRECT AND ACCURATE MEANS OF DETERMINING THE OPERATING CONDITION OF THESYSTEM. SHORT OF SEPARATING THE FLUID PHASES, THE ONLY MEANS OF DETERMINING BOTH THE MASS FLOW RATE AND FLOW QUALITY IN A TWO-PHASE FLOW IS TO MAKE SIMULTANEOUS, COMPLEMENTARY MEASUREMENTS AND TO PROCESS THE READINGS USINGAN APPROPRIATE ANALYSIS. THIS TECHNIQUE, CALLED HYBRID FLOWMEASUREMENT, HAS BEEN OF LIMITED APPLICABILITY IN THE PAST BECAUSE OF THE LIMITED TURNDOWN ACHIEVABLE WITH MOST VOLUME FLOWMETERS. THE BEARINGLESS FLOWMETER IS A VOLUMETRIC FLOWMETER THAT APPEARS TO OFFER THE DESIRED TURNDOWN PERFORMANCE. IN THE PROPOSED EFFORT, A HYBRID FLOWMETER CONSISTING OF A BEARINGLESS FLOWMETER AND A VENTURI FLOWMETER WILL BE EXAMINED AS A TWO-PHASE FLOWMETER IN A PRELIMINARY TEST PROGRAM. THE PROPOSED APPROACH HAS THE POTENTIAL TO OFFER MANY ADVANTAGES FOR USE IN A TWO-PHASE THERMAL MANAGEMENT SYSTEM, INCLUDING ACCURACY, RUGGEDNESS, LIGHT WEIGHT, LOW PRESSURE DROP, AND APPLICABILITY TO A WIDERANGE OF FLOW RATES AND QUALITIES.