Now showing items 69-88 of 89

    • 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 ...
    • Regenerator Friction Factor and Nusselt Number Information Derived from CFD Analysis 

      Cheadle, M. J.; Nellis, G. F.; Klein, S. A. (Georgia Institute of TechnologyICC Press, 2008-05)
      Macroscopic models used in the design and development of pulse tube cryocooler regenerators do not explicitly consider the complex microscopic interaction of the working fluid as it flows through the interstitial passages ...
    • Secondary Pulse Tubes and Regenerators for Coupling to Room-Temperature Phase Shifters in Multistage Pulse Tube Cryocoolers 

      Radebaugh, R.; O’Gallagher, A.; Gary, J. (Georgia Institute of TechnologyICC Press, 2008-05)
      Multistage pulse tube cryocoolers require separate phase shifters for each stage. For sufficiently high frequency and acoustic power, the inertance tube is commonly used for such phase shifting. For Stirling-type, multistage ...
    • 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 ...
    • Simulation of Boundary Layer Effects in the Pulse Tube of a Miniature Cryocooler 

      Conrad, T. J.; Ghiaasiaan, S. M. (Seyed M.); Kirkconnell, Carl Scott (Georgia Institute of TechnologyICC Press, 2008-05)
      As pulse tube cryocoolers are miniaturized, boundary layer effects in the pulse tube may become more important than they are for larger refrigerators. Nearly uniform flow in the pulse tube is necessary for efficient cooling, ...
    • SITP’s Miniature Coaxial Pulse Tube Cryocooler 

      Dang, H. Z.; Wang, L. B.; Wu, Y. N. (Georgia Institute of TechnologyICC Press, 2008-05)
      A single-stage miniature coaxial pulse tube cryocooler (PTC) has been developed in Shanghai Institute of Technical Physics, Chinese Academy of Sciences (SITP/CAS) to serve as a perfect substitute for an existing Stirling ...
    • Some Insights Into Stirling Machine Behavior 

      Tucker, A. S.; Gschwendtner, M. A.; Haywood, D. (Georgia Institute of TechnologyICC Press, 2008-05)
      Almost all practical cryocoolers embody, directly or indirectly, at least some elements of the Stirling cycle in its reversed form. Through its involvement in the analysis, design and development of both Stirling engines ...
    • Space Micro Pulse Tube Cooler 

      Nguyen, T.; Petach, M.; Michaelian, M.; Raab, J.; Tward, E. (Georgia Institute of TechnologyICC Press, 2008-05)
      The Northrop Grumman space micro pulse tube cooler (micro) is a split configuration cooler incorporating a coaxial cold head connected via a transfer line to a vibrationally balanced back to back linear compressor. The ...
    • SPICA/SAFARI Sub-Kelvin Cryogenic Chain 

      Duband, L.; Duval, J. M.; Luchier, N.; D’Escrivan, S. (Georgia Institute of TechnologyICC Press, 2008-05)
      SPICA, a Japanese led mission, is part of the JAXA future science program and is planned for launch in 2018. SPICA will perform imaging and spectroscopic observations in the 5 to 210 mm waveband. The SPICA payload features ...
    • Study of 35 K Regenerator Performance Operating at High Frequency 

      Wang, B.; Fan, B. Y.; Zhou, Wenjie; Gan, Zhihua; Qiu, Limin (Georgia Institute of TechnologyICC Press, 2008-05)
      The objective of this paper is to observe the regeneration performance of three different regenerator materials including stainless steel screen, lead screen and lead sphere at 35 K and at a high operating frequency. A ...
    • A Study of a Miniature In-Line Pulse Tube Cryocooler 

      Sobol, S.; Katz, Y.; Grossman, G. (Georgia Institute of TechnologyICC Press, 2008-05)
      A miniature pulse tube cryocooler has been designed and tested in our laboratory. The main part of the cryocooler, consisting of an in-line assembly of aftercooler, regenerator, cold heat exchanger, buffer tube and hot ...
    • Theoretical and Experimental Investigation of 30 K Single Stage GM-Type Pulse Tube Cryocooler 

      Desai, S.; Desai, K. P.; Naik, H. B.; Atrey, M. D. (Georgia Institute of TechnologyICC Press, 2008-05)
      Theoretical modeling of thermodynamic performance plays an important role in the design and development of pulse tube cryocoolers. In the present work, a thermodynamic model of a GMtype double-inlet pulse tube cryocooler ...
    • Theoretical and Experimental Investigation of Flow Straighteners in U-type Pulse Tube Cryocoolers 

      Badgujar, A. D.; Atrey, M. D. (Georgia Institute of TechnologyICC Press, 2008-05)
      The U-type Pulse Tube Cryocooler (PTC) involves a change in the direction of gas flow as it proceeds from the regenerator to the pulse tube. The sharp U-bend has an adverse effect on pulse tube cooling action due to formation ...
    • Theoretical and Experimental Investigation on the Axial Temperature Mismatch and its Optimization for Coaxial Inertance Pulse Tube Cryocoolers 

      Wang, L. B.; Dang, H. Z.; Wu, Y. N.; Li, S. S.; Yang, K. X.; Xiong, C. (Georgia Institute of TechnologyICC Press, 2008-05)
      In a coaxial pulse tube cryocooler, the radial thermal conduction between the pulse tube and the regenerator has a large influence on cryocooler performance. Caused by the temperature mismatch between the pulse tube and ...
    • Thermal Dispersion and Convection Heat Transfer during Laminar Transient Flow in Porous Media 

      Pathak, M. G.; Ghiaasiaan, S. M. (Seyed M.) (Georgia Institute of TechnologyICC Press, 2008-05)
      Solid-fluid thermal interactions during unsteady flow in porous media play an important role in the regenerators of pulse tube cryocoolers. Pore-level thermal processes in porous media under unsteady flow conditions are ...
    • 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. ...
    • 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 ...
    • Thermodynamic Comparison of Two-Stage Pulse Tube Refrigerators for Two Different Configurations 

      Razani, A.; Fraser, T.; Dodson, C.; Roberts, T. (Georgia Institute of TechnologyICC Press, 2008-05)
      Using exergy analysis, control thermodynamic models of two-stage Pulse Tube Refrigerators (PTRs) are developed for two different configurations. The models assume that phase shift controllers exist that control the phase ...
    • A Three-Stage Stirling Pulse Tube Cryocooler Approaching 4 K 

      Cao, Q.; Qiu, Limin; Gan, Zhihua; Yu, Y. B.; Zhi, X. Q. (Georgia Institute of TechnologyICC Press, 2008-05)
      It is a great challenge for a Stirling Pulse tube cryocooler (PTC) to reach liquid-helium temperature, where there are promising applications such as superconducting digital electronics, midinfrared instrument, heterodyne ...
    • Vibration-Free, Hybrid Cryocooler for 4 K Space Applications 

      Zagarola, M. V.; Chen, W. (Georgia Institute of TechnologyICC Press, 2008-05)
      Future astronomical observatories and surveillance satellites utilizing infrared, far infrared, and submillimeter detectors will require long-life mechanical cryocoolers that provide cooling at temperatures down to 4 K. ...