Showing papers in "Cryogenics in 2004"

TL;DR: In this article, an improved header configuration of plate-fin heat exchanger is put forward in order to enhance the uniformity of flow distribution, based on the analysis of the fluid flow maldistribution for the conventional header used in industry, a baffle with small holes of three different kinds of diameters is recommended to install in the header.

TL;DR: In this article, a thermodynamic and heattransfer model has been developed to analyze different mechanisms of heat leak into the LNG fuel, and the effect of a number of buses fueled each day on the possible total fuel loss rate has been analyzed.

TL;DR: In this paper, the vibrations of the cold-stage and cold-head of a Gifford-McMahon (GM) and pulse-tube (PT) cryocoolers were measured separately to investigate their vibration mechanisms.

TL;DR: In this paper, a new combination of starting materials was developed to shorten the calcination time of the metalorganic deposition (MOD) process using metal trifuluoroacetete (TFA) salts for all elements.

TL;DR: In this article, the performance of two typical mixed-gases refrigeration cycle configurations was analyzed for cooling fixed-temperature heat loads and the results showed that the auto-cascade cycle can improve thermodynamic performance in the case of using mixtures with increased fraction of high-boiling components.

TL;DR: In this article, the critical temperature Tc of the superconductor Nb3Sn that includes the dependence on applied mechanical strain is calculated using the formalism of strong coupling phonon superconductivity.

TL;DR: In this article, the authors discuss the development of a continuous adiabatic demagnetization refrigerator (CADR) that meets the cooling requirements of the X-ray Microcalorimeter Spectrometer (XMS) instrument.

TL;DR: In this paper, the authors present the level of maturity of the hydrogen sorption cooler technology at JPL by describing the design and how it has been validated at the subsystem and system levels.

TL;DR: In this article, the authors present a completely closed-cycle refrigeration system consisting of four stages; the first two, 40.5 and 2.7 K, are provided by a pulse tube cooler, the third and fourth stages by helium adsorption refrigerators.

TL;DR: In this paper, the effect of the Lorentz forces on a multistrand NbTi conductor comparable to the present design for ITER in magnet operating conditions is investigated. But the results are limited to the case of a single strand.

TL;DR: In this article, a nodal analysis method for simulating inertance tube pulse tube refrigerators is introduced, where the energy equation, continuity equation, momentum equation of gas, energy equation of solid are included in this model.

TL;DR: In this article, the performance of a two-stage pulse tube cooler that consists of two parallel stages with independent gas circuits was investigated, and a minimum stationary temperature of 1.27 K was achieved.

TL;DR: In this paper, two kinds of new compliant foil journal bearing for a small cryogenic turbo-expander used in the Brayton cycle cryocooler are presented, which are supported with copper wires and elastic material respectively, so the bearings are much simpler in structure than previous compliant foil bearing.

TL;DR: In this paper, a subcooled liquid jet is used to control the pressure rise of a large cryogen storage tank in microgravity using a series of parametric numerical simulations.

TL;DR: In this article, the authors described the characteristics of a stationary linear type magnetic flux pump, which mainly consists of DC bias coil, 3-phase AC coil and Nb foil.

TL;DR: In this paper, a prototype of a 1 K-class cooling system for the Space Infrared Telescope for Cosmology and Astrophysics (SPICA) is presented, which consists of a two-stage Stirling and a Joule-Thomson (JT) cooler with 3 He as the working fluid.

TL;DR: In this article, the authors report on the slush hydrogen technology in terms of the measurement of the density and the mass flow rate, and show that at a solid fraction of within 50%, piped transport can be conducted in the same way as for normal fluids.

TL;DR: In this paper, the influence of variations of interface temperature on thermal contact conductance between aluminium and stainless steel joints was determined by modeling the deformation at the interface for different values of surface finish and contact pressure over the range of interface temperatures.

TL;DR: In this paper, the fault current limiting characteristics of a flux-lock type high-T c superconducting fault current limiter (HTSC-FCL) using series resonance between capacitor for series resonance and magnetic field coil which was installed in coil 3.

TL;DR: In this paper, the authors measured the thermal contact conductance of several demountable copper joints below 1 K. The joints were made by bolting together either two flat surfaces or a clamp around a rod.

TL;DR: Magnetization, AC loss, χ DC and d eff were measured for several designs of rod-in-tube based internal-Sn Nb 3 Sn type superconducting multifilamentary strands.

TL;DR: In this article, the authors describe development details and performance results of a high performance, highly reliable cryogenic thermal switch (CTSW), US Patent Number 6,276,144 B1, and a CTSW test bed.

TL;DR: In this article, a thermally optimized in-space zero boil-off densified cryogen storage system model is developed and used to model a spherical liquid hydrogen tank with active cooling and passive insulation systems.

TL;DR: In this paper, a three-dimensional two-phase mixture model along with the standard k-e mixture turbulence model is employed to study the turbulent mixing of the fluid-particle slurry system.

TL;DR: A numerical method for regenerators is introduced, suitable for the regenerators in cryocoolers and Stirling engines, but also suitable forThe stacks in acoustic engines and the pulse tubes in pulse tube refrigerators.

TL;DR: In this paper, a general strain invariant formulation of T c in strong superconductivity is presented in which the phonon frequency spectrum is represented through generalized elastic stiffness coefficients that include strain dependence.

TL;DR: A laminate screen matrix regenerator with 47 elements has been designed, analyzed, fabricated and tested in this paper, where the regenerator flow resistance, thermal conductance losses, dead volume, surface area and heat transfer coefficient are analyzed.

TL;DR: In this article, a new calculation model was proposed to provide the relation between the electromagnetic force and hydraulic characteristics of the conductor, which can explain the deformation of the cable shape in the CS insert conductor due to an electromagnetic force acting on the cable.

TL;DR: In this article, the effect of transverse compressive stress on critical current was explored for a standard Nb 3 Sn wire and a Cu-NbTi-reinforced Nb3 Sn wire.