LOW FILM RESISTANCE CONDENSER FOR OPERATION IN A GRAVITY-FREE ENVIRONMENT

TWO-PHASE THERMAL TRANSPORT LOOPS OFFER SIGNIFICANT WEIGHT AND PERFORMANCE ADVANTAGES OVER CONVENTIONAL SINGLE-PHASE SPACECRAFT THERMAL MANAGEMENT SYSTEMS. KEY COMPONENTS IN TWO-PHASE THERMAL MANAGEMENT SYSTEMS ARE THE CONDENSING AND EVAPORATING HEAT EXCHANGERS TO COUPLE THE LOADS TO THE TWO-PHASE THERMAL BUS, AND TO TRANSFER HEAT BETWEEN THE THERMAL BUS AND THE SPACECRAFT RADIATOR. THE MAIN REQUIREMENTS FOR THESE HEAT EXCHANGERS ARE THAT: 1) THEY CONTROL THE LOCATION OF MANAGE THE GAS AND LIQUID PHASES IN THE ABSENCE OF GRAVITY AND 2) THEY HAVE HIGH HEAT TRANSFER COEFFICIENTS; THAT IS, THEY OPERATE AT HIGH HEAT FLUXES WITHLOW OVERALL TEMPERATURE DIFFERENCES. A NOVEL CONDENSING HEAT EXCHANGER CONCEPT WHICH HAS THE POTENTIAL TO OPERATE AT HEAT TRANSFER COEFFICIENTS AN ORDER OF MAGNITUDE LARGER THAN IS POSSIBLE WITH CURRENT DESIGNS ISPROPOSED. PHASE I OF THIS PROJECT WILL ASSESS THE FEASIBILITY OF THE PROPOSED HEAT EXCHANGER BY PERFORMING A PROOF-OF-CONCEPT EXPERIMENT AND DEVELOPING SCOPING ANALYSES TO ESTIMATE ITS EXPECTED RANGE OF PERFORMANCE. IF PROVEN FEASIBLE, A PROTOTYPE HEAT EXCHANGER WILL BE BUILT AND TESTED IN PHASE II.