MEASUREMENT OF REVERSING FLOW PRESSURE DROPS IN STIRLING ENGINE HEAT EXCHANGERS

ONE OF THE IMPORTANT FACTORS AFFECTING STIRLING ENGINE EFFICIENCY AND PERFORMANCE IS THE PUMPING LOSS THROUGH THE HEAT EXCHANGER LOOP. THE FLOW THROUGH THESE HEAT EXCHANGER LOOP. THE FLOW THROUGH THESE HEAT EXCHANGERS IS OSCILLATORY, A CONDITION FOR WHICH SUFFICIENT TEST DATA DOES NOT EXIST. IT HAS BEEN REALIZED FROM ENGINE TEST RESULTS THAT THE PRESSURE DROP THROUGH THIS LOOP MUST BE GREATER THAN THAT PREDICTED USING STEADY UNIDIRECTIONAL FLOW DATA. PHASE I OF THIS PROJECT IS TO DESIGN A TEST RIG WHICH CAN BE USED TO ACCURATELY MEASURE THIS OSCILLATORY FLOW PRESSURE DROP THROUGH HEAT EXCHANGERS AND REGENERATORS OVER A WIDE RANGE OF OPERATING FREQUENCIES AND MEAN PRESSURES. FABRICATION OF THE HARDWARE WOULD BE PERFORMED UNDER PHASE II. ALSO UNDER PHASE II, TESTING OF MANY CONFIGURATIONS OF HEAT EXCHANGERS AND REGENERATORS WOULD BE PERFORMED FOR SEVERAL WORKING FLUIDS. THIS WOULD RESULT IN VALUABLE INFORMATION FOR THE DESIGN AND OPTIMIZATION OF STIRLING ENGINES, IN BOTH THE NASA AUTOMOTIVE STIRLING PROGRAM AND THE NASA SPACE POWER PROGRAM.