OSCILLATING FLOW IN STIRLING MICROREFRIGERATORS: EMPIRICAL VERIFICATION OF ANALYTICAL RESULTS

SUCCESS IN THE INTERNATIONAL COMPETITION TO IMPROVE ELECTRONIC SYSTEMS DEPENDS UPON THE DEVELOPMENT OF BETTER MEANS FOR REMOVING HEAT AND PRODUCING LOW TEMPERATURES. COMPARED TO CURRENT TECHNOLOGY, THE REQUIRED REFRIGERATORS MUST BE MORE COMPACT AND RELIABLE, REQUIRE NO MAINTENANCE ORSKILL TO OPERATE, ACHIEVE MUCH LONGER OPERATING LIFETIMES, AND PUMP UP TO SEVERAL WATTS OF HEAT, YET COST ONLY A SMALL FRACTION OF THE REST OF THE ELECTRONIC SYSTEM. THESE OBJECTIVES ARE NOT ACHIEVED IN PRACTICE DUE TO MECHANICAL, THERMAL, AND FLUID FLOW IRREVERSIBILITIES WHICH ARE INHERENT IN CONVENTIONAL DESIGNS, MATERIALS, AND MANUFACTURING PROCESSES. THROUGH SILICON MICROMACHINING, HOWEVER, FUNDAMENTALLY LOSSY MECHANICAL COMPONENTS CAN BE ELIMINATED AND SPECIAL MATERIALS PROPERTIES CAN BE EXPLOITED, WHILE THERMAL AND FLUID FLOW CONTRIBUTIONS TO ENTROPY GENERATION CAN BE CONTROLLED. UNDER CURRENT NSF SGER FUNDING WE ARE DERIVING ENTROPY MINIMIZATION FUNCTIONS FOR OSCILLATORY FLOW AND DESIGNING ANEXPERIMENTAL APPARATUS WHICH IS THERMALLY AND FLUID-DYNAMICALLY SIMILAR TO A PRELIMINARY STIRLING MICROREFRIGERATOR DESIGN. WE PROPOSE TO CONSTRUCT THIS APPARATUS TO VALIDATE THIS DESIGN IN PHASE I AND TO EMPIRICALLY VERIFY OUR ANALYSES OF OSCILLATORY FLOW IN PHASEII. SUCCESSFUL RESULTS WILL PROVIDE A FOUNDATION FOR THE ENGINEERING OF STIRLING MICROREFRIGERATORS THAT WILL GREATLYEXPAND THE RANGE OF APPLICATIONS FOR COLD ELECTRONICS.