Experimental results on the electrical and thermal characteristics of GdBCO racetrack coils co-wound with stainless steel (SS) tapes of various thicknesses and winding tensions are presented in this paper. The SS thickness and winding tension are identified as the factors affecting the charging time and thermal stability of metal insulation (MI) coils. To verify these characteristics, three types of

The multi-nozzle spray cooling with liquid nitrogen can achieve high heat transfer rate and uniform temperature for a large-scale environmental simulation system. The understanding of the flow characteristics is crucial to the accurate control of the mass flow rates and the temperature distribution in a cryogenic system. This article combines the experimental and numerical approach to reveal the external

In cryogenic conditions, a Pulsating heat pipe (PHP) can be used to transport a high heat flux across a relatively small temperature difference. Using empirical techniques to design such a PHP is unreliable due to the shortage of experimental dataset available for cryogenic operation. A numerical model developed for cryogenic temperatures and compared with experiments conducted at those temperatures

Cryogenic system working at 2 K is crucial for superconducting accelerator. A 70W@2 K cryogenic system was developed for the testing of superconducting cavities used in the China Initiative Accelerator Driven System (CiADS). There will be more than 257 superconducting radio frequency(SRF)cavities to be vertically tested in the next three years. The system is designed with 2 testing dewars and the cool

Bi2SrxCa2Cu3O10+δ (Bi-2223) precursor powders were fabricated by co-precipitation process with different Sr content of x=1.93, 1.90, and 1.85. Multi-filamentary Bi-2223 high temperature superconducting tapes were fabricated by the traditional powder in tube process (PIT) with different precursor powders. The influences of Sr content on the phase formation dynamics as well as the superconducting properties

We have investigated the electrical transport, magnetotransport and magnetic properties of (1-x) La0.7Sr0.3Mn0.94Co0.06O3(LSMCO)/x ZnO (x = 0, 0.04) composite samples to explore the role of the secondary phase. The results of Rietveld refined X-ray diffraction (XRD) data show that the prepared LSMCO sample possesses a rhombohedral structure in the hexagonal lattice and the same reveal that both the

There are two main obstacles in front of the development of high temperature superconducting (HTS) technology for electric power network applications; tape price and cooling cost. In order to reduce cooling cost, it is vital to evaluate AC transport current loss of the tapes precisely and then reduce it by some design innovative approaches. In addition, AC transport current loss in HTS material is

This study aims to investigate the impacts of thermal effect on cavitation, entropy features and interactions among vorticity, force coefficients and entropy production rate (EPR) in a liquid nitrogen cavitating flow. Numerical results demonstrate that the increase in free-stream temperature intensifies thermal effect and weakens cavitation intensity. The EPR by fluctuating velocity gradient (ṠD'''')

A cryogenic twin-screw extruder for plasma fuelling is under development at Institute for Plasma Research (IPR), India. The fuel for Indian tokamaks SST-1 and Aditya-Upgrade is injected in the form of frozen hydrogen pellets; the current injector design has a pipe gun based concept, cooled by a GM-cryocooler. An advanced fuelling system will produce hydrogen pellets continuously using a twin-screw

An enhanced midstream design method for cryogenic turbomachines is presented in this article by reformulating that given by Hasselgruber and Balje. The enhanced formulation incorporates non-idealities such as turbomachinery inefficiency and flow angle deviation. Moreover, certain other issues faced by high speed cryogenic turbomachinery operating in low temperature domains, such as those arising due

Heat transfer from inner surface of a vertical heated pipe to subcooled or saturated liquid hydrogen flowing upward was measured for quasi-steadily increasing heat input up to fully developed film boiling regime and decreasing the heat input through the film boiling regime. The experiments were carried out at the inlet pressures of 400, 700 and 1100 kPa and subcoolings from 0 K to 11 K. Three test

Helium has the lowest boiling point of any element in nature at normal atmospheric pressure. Therefore, any unwanted substance like impurities present in liquid helium will be frozen and will be in solid form. Even if these solid impurities can be easily eliminated by filtering, liquid helium may contain a non negligible quantity of molecular hydrogen. These traces of molecular hydrogen are the causes

In this study, a small-scale natural gas liquefaction device was built to verify the feasibility of optimization results of the dual nitrogen expansion natural gas liquefaction process with pre-cooling. From the thermodynamics perspective, the feasibility of using R22 instead of propane as a pre-cooling refrigerant, and nitrogen instead of natural gas as the feed gas was verified. Furthermore,a genetic

Optimisation design of gas-liquid packed column filled with structured packing during the absorption process requires an accurate prediction of the liquid distribution. A two-dimensional computational fluid dynamics (CFD) model is developed for the structured packed column which is applied in floating liquefied natural gas (FLNG) in offshore platforms. And several user-defined functions (UDFs) based

A hybrid refrigerator combining Gifford-McMahon (GM) gas expansion refrigeration with magnetic refrigeration, in which helium and magnetic materials regenerate each other, overcomes the low-temperature thermal saturation of regenerator materials and has been experimentally proved to reach a higher cooling power than pure GM refrigeration recently. Considering the complexity of the thermodynamics and

In a typical pulse tube cryocooler application, modeling the cool-down dynamics of a load attached to the cold tip require knowledge of the transient cooling power. Although this data may be calculated for in-house developed cryocoolers, the only data provided in commercial off-the-shelf cryocoolers is the steady state cooling power. In this paper, we show a systematic approach to derive transient

It is important to discriminate between mechanical strain and thermal output (apparent strain) in fiber Bragg grating (FBG) strain sensors, due to their sensitivity to both mechanical strain and thermal output. Additionally, when FBG sensors are directly bonded on monitored structures, the transverse effect and the strain-transfer error must be considered to correctly measure the strain. The objectives

A theoretical investigation to optimize thermoelectric modules for maximization of cooling capacity is performed using a novel one-dimensional analytic model, in which the thermal resistances of heat exchangers as well as the thermal and electrical contact resistances inherent in the modules are taken into account. New dimensionless parameters are introduced to avoid the difficulties in optimizing

A small-scale mobile liquid helium cryogenic system has been designed for the cooling of a superconductive single-flux-quantum circuit. The system includes a unique double inner cylinder, a “zigzag” cold energy recovery structure for the coaxial line and a special magnetic shielding structure. Experiments were conducted to test the thermal performance and the magnetic shielding efficiency of the liquid

The purpose of this study was to investigate a parameterized mathematical approach for estimating the complex modulus of a polyimide film at extreme cryogenic temperatures (e.g. 4 K). Such films are used in extreme cryogenic applications such as superconducting magnets and electronic devices. A polymer core of the electronic laminate, Pyralux AP8525R (polyimide), was tested on a TA Instruments Q800

In this paper a holistic optimization method of MR J-T mixture composition based on steepest descent method is developed and comprehensively presented. Modelling is carried using Peng-Robinson EoS available in RefProp 10. The optimization tool takes into account many different factors, that are usually applied separately, like minimum temperature approach in recuperative heat exchanger (which corresponds

Raw natural gas is composed of several hydrocarbons, incombustible gases, such as nitrogen and helium, and impurities. While all the impurities are typically rejected at the beginning of the process, the removals of the two inert gases are postponed to last steps, where almost all the hydrocarbons except methane are already produced in an NGL recovery unit. Hence, NGL recovery, nitrogen removal and

Mechanical applications for polymers at cryogenic temperatures are extremely limited due to decreased atomic mobility and ductility, resulting from glass transitions above the cryogenic regime (<120 K). As such, polymeric materials are known for cracking and low fatigue life. Crumpling polymer films has been historically researched as a mechanism to bypass this brittleness for mechanical actuation

The Stirling cryocoolers are widely used in the military and the aerospace fields due to many advantages such as high efficiency and compact structure. The output performance is affected by three parameters: compressor stroke, expander stroke, and the phase shift between them. How to quickly and effectively adjust the three parameters to meet the required cooling capacity with a higher COP is of great

For two-phase refrigerant flow, the maldistribution at the entrance of plate-fin heat exchangers (PFHEs) is a severe issue which tends to make the thermal performance of heat exchangers worse. Especially when PFHEs are applied in the field of liquefied natural gas (LNG), the non-uniformity restricts the natural gas liquefaction efficiency of PFHEs. To improve the thermal performance and liquefaction

This paper presents a set of dynamic simulations performed on the future High Luminosity Large Hadron Collider (HL-LHC) cryogenic system. The objectives of these simulations are to provide main pressure, temperature and flow transients over the cryogenic distribution system around the collision points 1 and 5 during the forecast beam operation. These simulations serve the different cryogenic system

The effects of Ta substitutions on the superconducting properties of (Tl1−xTax)(BaSr)CaCu2O7 for x = 0, 0.1, 0.2 and 0.3 are reported. X-ray diffraction patterns showed a single Tl-1212 phase for the x = 0 samples. Unreacted Ta2O5 peaks were observed in all Ta substituted samples. The electrical resistance versus temperature curves showed metallic normal state behavior. The transition temperature and

We generated a three-dimensional stress map of grains and grain boundaries in uniaxial strained Nb3Sn composite, using a scale-coupled model generated by the polycrystalline finite element method and based on the linear elastic theory of closely packed fiber-reinforced composites. The model takes into account the transfer of stress from a Cu-Sn matrix to a single Nb3Sn filament composed of inner elongated

This study delves into three main subjects: (I) A strong definition on the variation of fundamental key mechanical design performance and general mechanical characteristic features founded on the formation of active operable slip systems and elimination of structural problems in the Tm substituted Bi-site Bi2.1-xTmxSr2.0Ca1.1Cu2.0Oy (0.00 ≤ x ≤ 0.30) ceramic materials; (II) Preference of propagation

The global custody transfer market for liquefied natural gas (LNG) has grown at a strong pace in the last decade and use of LNG as transport fuel has considerable environmental benefits. The quantity of LNG is traded on the basis of energy transferred, calculated from volume, density and gross calorific value. High-speed, accurate density measurement is therefore of significant commercial value. The

The rising share of renewable energy in the European grid creates a demand for long-length, high-power transmission lines. Superconducting cables represent an attractive option for such connections, offering considerable savings in energy and space for installation. Due to its low cost, the MgB2 superconductor might be an interesting choice, but it requires to be operated at very low temperature. In

Integrating superconducting elements in an electric motor can greatly increase its power density. By doing so, lighter and more powerful machines can be produced for applications such as aviation, wind turbines and marine propulsion. Superconducting tapes can be stacked and magnetised to produce powerful trapped-flux magnets. The experimental setup was designed to allow measurements in a low temperature

This research presents the influence of pyrene (C16H10) addition (0, 2, 4, 6, 8, 10 wt%) on the superconducting properties of bulk MgB2. For C16H10 added MgB2 samples, a shrinkage in a-lattice parameters was determined, whereas c-lattice parameters remained practically unchanged. The (1 1 0) peak observed at 2θ ≈ 59.9◦ slightly shifted to higher angles, the lattice strain increased and the crystallite

The new Nb3Sn superconducting magnet system for the fourth-generation 45 GHz ECR source is under development at the Institute of Modern Physics (IMP). A mirror structure of the Nb3Sn sextupole testing coil based on an aluminum shell-based structure and bladder & key technology is used for studying the coil's mechanical, thermal and quench performance under realistic conditions. This paper describes

Under the support of the China State Grid Corporation Science and Technology Project, a set of 10 kV superconducting fault current limiter (SFCL) with bias magnetic field including a high temperature superconducting a low inductance unit, a double split reactor, a fast breaker and its control system is designed and assembled in Hushitai high voltage center of Electric Power Research Institute of State

The thermal behavior of cryogenic propellant tanks is crucial issue in the operation of cryogenic propulsion systems. Herein, ground experiments were conducted in a 600-mm-diameter cryogenic tank filled with liquid nitrogen. As pre-pressurants, gaseous helium and gaseous nitrogen (of the same species as the liquid), were used to investigate its effect in accordance with actual propulsion systems. The

The European DEMOnstration Fusion Power Plant (EU-DEMO) is being designed as an intermediary stage between the ITER experimental reactor and future commercial fusion power plants. The EU-DEMO is based on the tokamak concept with a fully superconducting magnet system. The Central Solenoid (CS) of the EU-DEMO will consist of five modules, namely: CSU3, CSU2, CS1, CSL2 and CSL3, located vertically one

This paper presents a numerical study on the pressure wave traveling in the condensing flow of the liquid and vapor oxygen in the tank-to-engine propellant feedline of liquid rocket. A computational fluid dynamics (CFD) model is developed based on Eulerian multiphase model, and the coupling of pressure wave and flow condensation is achieved through incorporating user-defined functions (UDF) with interphase

Single crystals of n-Bi-Sb solid solutions with Sb content of 7–15 at.% are the most efficient thermoelectric (TE) materials over the temperature range of T ≤ 200 K. However, the use of these materials for construction of real thermoelectric devices are limited due to low mechanical strength. In this paper, for strengthening Bi-Sb single crystals, the method of the extrusion in a liquid medium under

The design of thermal insulation system is crucial for the LNG cargo containment system (CCS). In this paper, a heat transfer model for a 40 m3 independent type B mock-up tank was proposed. A cryogenic test platform was built and the liquid nitrogen boil off rate (BOR) of the mock-up tank was simulated and tested. Consistency between simulation results and test results verified the accuracy of the

At the booster turbopump exit of a high pressure staged combustion cycle based cryogenic rocket engine, hot gaseous oxygen after driving the booster turbine mixes with subcooled liquid oxygen from the booster pump leading to a complex phenomena of direct contact condensation of hot oxygen gas. The aim of the present investigation is to numerically study the condensation of oxygen vapor jets in subcooled

Coaxial pulse tube cryocoolers are the configuration of choice as they allow better access to the cold head. Hence, a previously built and tested in-line pulse tube cryocooler which uses an active displacer for phase control has been modified into a coaxial configuration. The active displacer allows the mass flow and the pressure pulse at the cold end of the pulse tube to be easily adjusted for optimum

The modification upon Sb doping on Ba-site of YBa2-xSbxCu3O7-δ superconductor on its electronic behaviour has been studied by applying the Density Functional Theory (DFT) via first principle study. The properties were investigated via computational simulation adopting CASTEP computational code. The crystal structure was constructed and calculated using Visual Crystal Approximation (VCA) with Generalized

Cryocoolers can experience near-periodic heaving or side-to-side motion and acceleration in some applications, in particular on moving platforms. In this work, the effect of heaving and rolling (side-to-side movement) on a Stirling pulse tube cryocooler was experimentally studied. Periodic heaving and rolling motions with various amplitudes, and frequencies in the 0.2 to 0.8 Hz range were imposed on

This paper presents the application of cryogenic natural circulation loop for engine cooling of launch vehicles, and the experimental measurements of the natural circulation system. The experimental results indicate that the circulation flow rate increases with an increase in heat input and a decrease in system pressure, on varying them. The study includes the temperature and pressure profiles of the

Cryogenic wind tunnel is an equipment for the requirement of high Reynolds number test of the aircraft via the method of reducing the test temperature. However, the test validity is extremely possible to be destroyed by the occurrence of condensation in cryogenic environment. To understand the characteristics of condensation flow over the airfoil, a two-phase flow was developed with the help of ANSYS

In this work we evaluate the performance of various electrical conductors, both normal-state and superconducting, at cryogenic temperatures with an eye towards motor, generator, and power transmission applications for use in all-electric and more-electric aircraft. In addition to MgB2 and YBCO superconductors, we consider high purity Cu and Al as well as carbon-nanotube (CNT) yarn. We analyze the normal-state

This paper reviews the literature published since 1994 related to the behaviour of composite materials at low and cryogenic temperatures. The material properties addressed are: tensile, compressive and shear strength, elastic modulus and stress-strain behaviour; mechanical and thermal fatigue response; fracture toughness; impact resistance; thermal expansion and thermal conductivity; tribology and

Cryogenic heat transport technologies are critical for integrating many space payloads. These technologies can be applied to address several payload integration issues: They allow isolation of the cryocooler from vibration-sensitive instruments, provide the ability to remotely mount the cryocooler from objects to be cooled and/or provide ability to cool remote or distributed loads. In comparison to

Cryogenic fluids such as Liquid Helium (LHe), Liquid Nitrogen (LN2), Liquid Oxygen (LOX) and Liquid Hydrogen (LH2) played a vital role in cooling various superconducting devices. The boiling temperatures of cryogenic fluids being lower than the critical temperature of the superconductors have enabled such an advantage. Moreover, supercritical fluids such as Supercritical Helium (SHe) and Supercritical

The number of turns is an important geometric parameter of the pulsating heat pipe. Currently, there is no criterion for selecting the number of turns. To study the effects of the number of turns, two hydrogen closed-loop pulsating heat pipes were tested with 2 turns and 5 turns, respectively. Other parameters were kept the same. To eliminate the influence of the condenser temperature, the condenser

A pulse tube refrigerator capable of work recovery operating at liquefied natural gas temperature (~110 K) is developed in this paper. Base on the thermoacoustic theory, an electro-acoustic circuit model is proposed to find the optimum working state, and the axial distributions of the key thermodynamic parameters including pressure, mass flow and phase difference between them, as well as the thermoacoustic

The main goal of this study is to investigate the effect of natural gas composition on the Joule–Thomson coefficient and Joule-Thomson inversion curve. The Joule-Thomson inverse curve is the geometrical location of points where the Joule-Thomson coefficient is zero. The curve is an important parameter for the liquefaction capability of natural gas. The GERG-2008 equation of state is utilized to calculate

The features of the Joule's energy dissipation in a composite high-temperature superconductor with a power equation of the voltage-current characteristic cooled by liquid helium or hydrogen are discussed. It is shown that the non-standard thermal stabilization conditions of composite superconductors can exist if the nonlinear temperature dependences of the electrical resistivity of the stabilizing

The cryostat equipped with superconducting materials is one of the most important component of high-temperature superconducting maglev vehicles. However, due to the multiple energy disturbance forms in the cryostat, such as AC losses of superconductors, vibration of the cryostat and so on, the evaporation of liquid nitrogen (LN2) will be stimulated to accelerate, which will seriously threaten the vehicle

In support of NASA’s Triton Hopper project, mechanical response data for solid nitrogen are needed for concept validation and development. Available mechanical properties data is sparse with only three known indentation measurements existing between 30 and 40 K. To generate more data, a custom instrumented hardness tester was developed to interface with a cryostat. The system was used to conduct cylindrical

At KEK, the superfluid helium cryogenic systems employ laminated-finned type 2 K heat exchangers (2 K HX). Their purpose is to sub-cool normal liquid helium (He I or LHe) from 4.4 K to 2.2 K or above, using the sensible heat carrying capacity of 2.0 K gaseous helium (GHe). This would help in reducing vapor flash losses during the Joule-Thomson (JT) expansion, hence improving the production rate of

MgB2 superconductors can be proposed as a good candidate for Maglev systems due to their superior structural and superconducting properties. Besides, magnetic levitation and guidance force properties of these superconductors should be increased for commercial applications of Maglev systems. Therefore, the critical current density and magnetic levitation and guidance force properties of MgTi0.06B2 superconducting

Gas liquefaction is one of the main applications of cryogenics science. Due to the unique properties of Helium, it can be used for several important applications. Therefore, appropriate and applicable analysis should be used to investigate and optimize the Helium liquefaction cycles. In the current study, the focus will be identifying the optimal point of the Collins’ cycle by performing energy and

Abstract Cryogen-free dilution refrigerators generally simplify low temperature research but some types of samples, including superconducting qubits and other nanoelectronic devices, are affected by environmental heat sources such as stray photons or residual helium. We present the design and performance of a hermetic cell installed on the mixing chamber plate of a cryogen-free dilution refrigerator