Now showing items 21-40 of 89

    • Liquid Nitrogen Energy Storage Units 

      Afonso, J.; Catarino, I.; Martins, D.; Duband, L.; Patrício, R.; Bonfait, G. (Georgia Institute of TechnologyICC Press, 2008-05)
      The energy storage units (ESU) described in this article are to be attached to the cold finger of a cryocooler with the objective of holding the low temperature environment constant while the cooler may be temporarily ...
    • Pulse Tube Cooler with Remote Cooling 

      Raab, J.; Maddocks, J. R.; Nguyen, T.; Toma, G.; Colbert, R.; Tward, E. (Georgia Institute of TechnologyICC Press, 2008-05)
      Space pulse tube coolers are very efficient, but like all regenerative high frequency Stirling and pulse tube coolers, the cold head needs to be located near the compressor in order to minimize the input power to the cooler. ...
    • Inertance Tube and Reservoir Modeling: Meshing, Convergence and Friction Factors for Oscillating Flow 

      Dodson, C.; Razani, A.; Roberts, T. (Georgia Institute of TechnologyICC Press, 2008-05)
      Pulse tube refrigerators (PTRs) have made dramatic improvements in reliability, efficiency and usage, with the addition of the inertance tube helping to create the improvements. The combination of the inertance tube and ...
    • Development of High Efficiency 4 K Two-Stage Pulse Tube Cryocooler 

      Xu, M.; Takayama, H.; Nakano, K. (Georgia Institute of TechnologyICC Press, 2008-05)
      Sumitomo Heavy Industries has been continuously improving the efficiency of our 4K pulse tube cryocooler in order to make it exchangeable with our 4K GM cryocooler. In order to improve the performance, three development ...
    • Effect of the Charged Pressure on GM Cryocooler Performance. 

      Nezuka, H.; Nakagome, H.; Ota, M.; Numazawa, T.; Masuyama, S.; Nakashima, N.; Ikeya, Y. (Georgia Institute of TechnologyICC Press, 2008-05)
      This paper presents experimental results that show that the refrigeration efficiency of GM refrigerators can be improved by applying a charged pressure. Recently, there has been remarkable progress in superconducting ...
    • Effect of Frequency on Hydrodynamic Parameters of Mesh Fillers in Oscillatory Flow 

      Landrum, E. C.; Conrad, T. J.; Pathak, M. G.; Ghiaasiaan, S. M. (Seyed M.); Kirkconnell, Carl Scott; Crittenden, Thomas M.; Yorish, S. (Georgia Institute of TechnologyICC Press, 2008-05)
      An experimental investigation was carried out to determine the effect of frequency on the porous media hydrodynamic closure relations for steady periodic flow. Using room temperature helium as the working fluid, stacked ...
    • Analysis of Multi-Stage Joule-Thomson Microcoolers 

      Cao, H. S.; Lerou, P. P. P. M.; Mudaliar, A. V.; Holland, H. J.; Derking, J. H.; Zalewski, D. R.; ter Brake, H. J. M. (Georgia Institute of TechnologyICC Press, 2008-05)
      Microcoolers machined from glass wafers based on Joule-Thomson (J-T) expansion have been investigated for many years at the University of Twente. After successful development of singlestage J-T microcoolers with a cooling ...
    • Measured and Calculated Performance of a High Frequency, 4 K Stage, He-3 Regenerator 

      Garaway, I.; Lewis, M. A.; Bradley, P. E.; Radebaugh, R. (Georgia Institute of TechnologyICC Press, 2008-05)
      Efficiencies of small 4 K cryocoolers are less than 1% of Carnot, whereas 80 K cryocoolers achieve efficiencies of up to almost 20% of Carnot. The primary loss mechanisms in low temperature regenerative cryocoolers are ...
    • Effect of Heat Exchanger Configuration on the Performance of Joule-Thomson Refrigerators 

      Hong, Yong-Ju; Park, Seong-Je; Choi, Young-Don (Georgia Institute of TechnologyICC Press, 2008-05)
      A typical Joule-Thomson (J-T) refrigerator consists of a recuperative heat exchanger, a gas expansion nozzle, a mandrel, and a compressed gas storage bottle. The thermodynamic performance of a J-T refrigerator depends ...
    • A 2 K Active Magnetic Regenerative Refrigeration System for Remote Cooling. 

      Chen, W.; McCormick, J. A.; Zagarola, M. V. (Georgia Institute of TechnologyICC Press, 2008-05)
      This paper reports on the development of an Active Magnetic Regenerative Refrigeration (AMRR) system for space applications. The AMRR can continuously provide remote/distributed cooling at about 2 K and reject heat at ...
    • Performance and Mass vs. Operating Temperature for Pulse Tube and Stirling Cryocoolers 

      Ladner, D. R. (Georgia Institute of TechnologyICC Press, 2008-05)
      Single stage pulse tube and Stirling cryocooler data that were reported in the open literature during the past decade were analyzed to find mathematical scaling laws for estimating the required input power and mass, as ...
    • Progress in the Development of the IXO 50 mK Sorption-ADR stage 

      Duval, J. M.; Luchier, N.; Duband, L.; Tirolien, T. (Georgia Institute of TechnologyICC Press, 2008-05)
      The nominal temperature of the new generations of detectors for the next space mission International X-ray Observatory (IXO) is expected to be around 50 mK. The coupling of a 3He cooler with an ADR provides an elegant ...
    • Thermal Storage Unit Using the Triple Point of Hydrogen 

      Charles, I.; Coynel, A.; Daniel, C. (Georgia Institute of TechnologyICC Press, 2008-05)
      The French space agency (CNES) has co-funded a Research and Technology program and CEA/SBT has developed a 14 K thermal storage unit using the triple point of hydrogen. The development unit is able to store 10 J at 14 K. ...
    • Demonstration of a Cryogenic Boil-Off Reduction System Employing an Actively Cooled Thermal Radiation Shield 

      Feller, J. R.; Plachta, D. W.; Mills, G.; McLean, C (Georgia Institute of TechnologyICC Press, 2008-05)
      NASA, under the Cryogenic Fluid Management (CFM) Project, in partnership with Ball Aerospace Technologies Corporation (BATC), conducted a reduced boil-off demonstration employing an actively cooled thermal radiation shield. ...
    • Application of New Figures of Merit for Multi-Stage Cryocoolers 

      Delmas, J.; Kadin, A. M.; Webber, R. J.; Track, E. K. (Georgia Institute of TechnologyICC Press, 2008-05)
      Evaluation of the overall performance of a multi-stage cryocooler, including the cooling power available on the intermediate stages, is not trivial, but is necessary to choose or design efficiently a cooler for a defined ...
    • Thermal Switching Cryogenic Heat Pipe 

      Bugby, D. C.; Cepeda-Rizo, J.; Rodriguez, J. I. (Georgia Institute of TechnologyICC Press, 2008-05)
      This paper describes a thermal switching cryogenic heat pipe, which is needed to thermally manage two CCD cameras within the ABC instrument on the NASA/JPL SIM Lite telescope. The primary requirement is to transport 12 W ...
    • Performance Test of Pulse Tube Cooler with Integrated Circulator 

      Maddocks, J. R.; Maddocks, P.; Fay, M.; Helvensteijn, B. P. M.; Kashani, A. (Georgia Institute of TechnologyICC Press, 2008-05)
      To address the need for remote and broad area cooling using regenerative cryocoolers, Atlas Scientific is developing a lightweight, continuous-flow Integrated Circulator (IC) for installation on Pulse Tube Cryocoolers ...
    • Reduction of Self Induced Vibration in Rotary Stirling Cycle Coolers 

      Bin-Nun, U. (Georgia Institute of TechnologyICC Press, 2008-05)
      Cryocooler is a major consideration in the design of IR imaging systems, especially when mounted on stabilized platforms with gimbals. The coolers in these types of applications induce forces and moments that interfere ...
    • Drive Electronics for Moving Magnet Type Linear Motor Compressor 

      Karunanithi, R.; Jacob, S.; Singh Gour, Abhay (Georgia Institute of TechnologyICC Press, 2008-05)
      An inexpensive drive circuit to operate a moving magnet type linear motor compressor up to 100 W power is described. It is a Pulse-Width Modulated (PWM-based) circuit with provisions to adjust the frequency, modulation ...
    • Self-Induced Vibration of NGAS Space Pulse Tube Coolers 

      Colbert, R.; Nguyen, T.; Raab, J.; Tward, E. (Georgia Institute of TechnologyICC Press, 2008-05)
      Space cryocoolers are often used to cool the focal planes and optics of telescopes. Since telescope and focal plane jitter can affect the clarity of the image, space cryocoolers are designed for inherent low vibration. For ...