Small Scale Cryogenic Refrigeration Technology

Virtual AeroSurface Technologies, Inc. and the Georgia Institute of Technology propose an STTR program for the investigation and modeling of meso scale Pulse Tube cryocooler systems (with initial design targets of 0.5 mW exergetic cold end thermal loads and cryocooler volumes of approximately 10 ml), with the possible extension of models further into the micro scale. CFD-based models will be developed specifically for operation at the meso scale focusing specifically on all relevant scale-sensitive phenomena (e.g., increased surface area to volume ratios with relatively greater friction and heat transfer losses, adverse heat conduction in the working fluid and solid structures, etc.). These models will be applied directly to the design and optimization of meso scale Pulse Tube cryocoolers, including both the fundamental size limitations for operation of such devices and the novel structures or subsystems which may be required for their successful implementation. The potential designs will be further considered and assessed from the standpoint of their manufacturing feasibility, including both conventional and MEMS-based fabrication techniques. A prospective Phase II follow-on program would extend beyond the design phase to fabricate breadboard experimental prototypes of the designed systems and their novel miniaturized components and fully characterize their performance and effectiveness.