Cavitation is a severe problem in rocket turbopumps. As for turbopumps with liquid oxygen, it exhibits notable thermodynamic effects during cavitation, leading to complex flow characteristic. In this study, to assess the influence of thermodynamic effects on the cavitation flow in a liquid oxygen turbopump, the entire flow passage was numerically simulated using the shear stress transport k–ω turbulence

In this paper, we report on the quantitative characteristics of the DC current transport property of a superconducting bismuth strontium calcium copper oxide (BSCCO) stator winding that is used in a superconducting motor. The winding is in a slot of silicon steel core, and the DC voltage of such a winding is measured as a function of the transport current in atmospheric liquid nitrogen. Precise distribution

Bending tolerance is one of the most fundamental mechanical properties of REBCO coated conductors for application to a superconducting coil. In this study, we investigated critical current degradation of REBCO coated conductors under bending and uniaxial tensile strain at 77 K and self-field with three different kinds of production from SuperPower Inc, Suzhou Advanced Materials Research Institute (SAMRI)

Cryogenic air separation plants produce pressurized oxygen gas at 150 bar and 99.8% purity to fill oxygen cylinders directly. It is either produced by compression in oxygen compressor (external compression) or pumping and vaporizing liquid oxygen in main heat exchanger by incoming air (internal compression). Small and medium-scale plants differ in the types of main heat exchanger, compression and expansion

The image quality in a MRI magnet greatly depends on the mechanical, thermal and electromagnetic performance of the thermal shield in presence of any time varying field. A detailed analysis on the mechanical resonance frequency, temperature distribution and the eddy current distribution on a thermal shield of a zero-boil-off cryostat for 1.5T MRI magnet system is presented. Five combination of aluminum

This paper presents the modeling results of a pressure-controlled tank-to-manifold propellant cross-feed system for liquid rockets. A transient dynamic model has been developed based on the bond graph theory using AMESim software, and the predicted pressure and flow rate histories are in good agreement with experimental data. The simulation results indicate that the pressure-controlled tank-to-manifold

The axial heat leakage between the cold and hot ends of the regenerator caused by the huge temperature difference is an important part of the cryocooler loss, where the apparent thermal conductivity of regenerator materials is the key parameter that determines the heat leakage. At present, only the apparent thermal conductivity of stainless steel wire mesh, lead and copper sphere above 80 K can be

Optimal energy management is a major challenge for most energy storage systems (ESSs), which is especially a big concern for the superconducting fault current limiter-magnetic ESS (SFCL-MES). To prevent malfunction, the superconducting coil (SC) current of the SFCL-MES needs to be controlled strictly within a well-defined operational range. To optimally utilize the energy capability of the ESS while

The cryogenic thermal conductivity of high-strength 7050 aluminum alloy subjected to the processes with different combinations of solution, aging and deep cryogenic treatment, was measured by a one-dimensional steady-state thermal conduction method. The microstructure evolution of this alloy after different treatments was also characterized to investigate the changes in thermal conductivity. The results

As an insertion device, the superconducting wiggler has been developed for about 40 years, the superconducting magnet of which is usually made of NbTi and set in a cryostat. The performance of the cryostat is vital to the success of the superconducting wiggler. In this paper, a cryostat of the superconducting wiggler with 32 poles and 2.6 T field for the High Energy Photon Source Test Facility (HEPS-TF)

The 4K Joule-Thomson (JT) cryocooler is a key cryogenic component for future astronomy missions such as ATHENA and LiteBIRD. It was originally developed for SMILES (2009) and upgraded for ASTRO-H/SXS (2016) and SPICA. The 20K two-stage Stirling cryocooler developed for AKARI (2006) was also upgraded and used as a precooler. The operational life is a critical factor in planning long-term missions. An

Flow boiling experimental data for liquid hydrogen (LH2), liquid methane (LCH4), and liquid oxygen (LO2) were compiled. The collected data represent saturated nucleate/forced convective evaporation boiling (pre-CHF), and film/dispersed droplet boiling (post-CHF). For LH2, pre-CHF data were compiled from six sources, and post-CHF data were compiled from 12 sources. Useful pre-CHF boiling data for LCH4

Experimental investigations of two variants of a high pressure ratio cryogenic turboexpander, from a new series of turboexpanders for Bhabha Atomic Research Centre (BARC), are presented in the article. Both the variants are designed based on an earlier reported enhanced midstream method. The new turboexpanders are designed with larger turbine impeller-diffuser radial clearances and smaller turbine

In this study, the effect of multi-walled carbon nanotube doping to MgB2 compound on microhardness properties of MgB2 was investigated by using solid-state reaction method. The amount of multi-walled carbon nanotubes was chosen as 0, 1, 2, 3 and 4% by weight of total MgB2. All samples were obtained by sintered at 650 °C temperatures. The microhardness properties of the samples obtained were examined

We developed a soft and high thermal conductive thermal link for cryogenic applications. The measured maximum thermal conductivity was approximately 18500 W/m/K at 10 K. This spring constant was 1/43 of that of a single thick wire with the same cross-sectional area at room temperature. We reached these performances by utilizing high purity aluminum (99.9999%, 6 N) and by stranding many thin wires that

Large-scale cryogenic refrigeration equipment is the sole way to realize the cryogenic environment for scientific facilities such as space technology, quantum computer and magnetic levitation. As one of the key moving components in cryogenic system, the helium compressor determines the reliability and performance of the whole cryogenic system. The twin screw compressor is a promising choice to be used

Oxygen sensors play a vital role in ensuring the safety of employees and users at the National High Magnetic Field Laboratory. While most oxygen sensors have accurate and linear responses in nitrogen/argon environments, studies have highlighted a phenomenon in helium-air mixtures with certain types of oxygen sensors. A controlled experiment was performed to observe the behavior of two types of oxygen

In this study, six cubic equations of state (CEoSs) were used to predict the Joule-Thomson coefficient (JTC), specific heat capacity (SHC), inversion curve (IC) and outlet temperature of the Joule-Thomson (JT) valve parameters. The accuracy of each CEoS was evaluated from the comparison of experimental data with obtained results. Of the six CEoSs, three-paramter CEoSs— Esmaeilzadeh and Roshanfekr (ER)

Submerged combustion vaporizer (SCV) is widely used as a device to vaporize liquefied natural gas (LNG) stored in cryogenic state, which is effective in peak shaving and emergency response in LNG vaporization stations and receiving terminals. In this paper, a heat transfer calculation model of SCV based on numerical calculation is established and its accuracy is verified by a practical case. Based

Radial force (radial stiffness) is an important performance index of radial HTS magnetic bearing. However, it is difficult to calculate it due to the complexity and particularity of the structure. It is of great significance to establish an effective and convenient method to predict the radial force of radial bearing. In this paper, the moving mesh of COMSOL Multiphysics® software is introduced into

A Dewar is the key structure of motors with high temperature superconducting (HTS) armature windings. Traditional Dewars use total immersion cooling, which can cause additional mechanical losses and challenges for rotary sealing. To avoid these problems, a novel Dewar structure was developed with partial immersion cooling. A 15 kW cryogenic induction motor with the designed Dewar was then developed

This paper conducts systematic theoretical analyses of a hybrid cryocooler composed of a four-stage Stirling-type pulse tube cryocooler (SPTC) and a Joule-Thomson cooler (JTC), in which the former provides the necessary precooling powers to the latter which aims at reaching a temperature of 1.0 K. The structural design of the hybrid cryocooler is described and its working mechanism focused on. Both

Magnetization AC loss measurements of singe- and seven-core Ba122/Ag tapes have been done by calibration-free method in the range of temperature from 20 K to 42 K and field magnitudes up to 70 mT in RMS with two frequencies 72 Hz and 144 Hz. A strong effect of eddy current losses in highly conductive Ag sheath was observed for single-core sample, but negligible for seven-core tape with more resistive

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

The experimental data accessible in the open literature related to pool boiling of liquid hydrogen (LH2), liquid methane (LCH4), and liquid oxygen (LO2) were compiled. Pool nucleate boiling of LH2 data were compiled from 17 sources, and pool film boiling of LH2 data were compiled from six sources. Pool nucleate boiling of LCH4 data were collected from eight sources, and useful data for pool film boiling

With the rapid development of aerodynamics for high speed aircraft, the flight experiments need to be carried out under ultra-high Reynolds number condition to simulate actual high-speed flight conditions, which puts forward higher requirements for the wind tunnel. Reynolds number increases rapidly as the decrease of the flow temperature because the viscosity of the working gas decreases and the density

The cooling systems of High-Temperature Superconducting (HTS) power transmission cables are unable to achieve the desired performance as prescribed in the cryogenic road map. Reverse Brayton cycle based Cryocooler (RBC) has been identified as a refrigerator that has the potential to achieve the desired performance for higher cooling load demand. In this article, an exergy analysis of the basic Reverse

This study evaluates the thermal expansion coefficient, as well as the elastic-, plastic- and fracture behaviour, at ambient and cryogenic (liquid nitrogen) temperatures, of four different epoxy systems that are used in high-field superconducting magnets, with the emphasis on rate-dependent plasticity as measured by uniaxial compression testing. As expected, both the elastic and plastic behaviour of

Spiral wound heat exchanger has compact structure, good thermal performance per volume and simple manufacture process. It is the key equipment for the superfluid helium cryogenic system, which is able to recover the cold capacity and improve the refrigeration effectiveness. To investigate the influence of fins structure on the thermal performance of spiral wound heat exchanger is essential for its

In this paper, a type of mutual inductance sensor based on the PCB technology is proposed for cryogenic radial displacement measurement. Firstly, the feasibility of the scheme is analyzed from the aspects of the low temperature usability of materials and components, and the temperature sensitivity of the sensor. Then the experiments at low temperature (77 K) and room temperature are carried out with

The measurements of self-fields and voltages for the stacked tapes assembled in rigid structure (STARS) conductor were carried out when the conductor immersed in liquid nitrogen was energized. In the measurements, a 3 m straight line shaped STARS conductor, which is composed of 45 REBCO tapes (15 tapes × 3 rows) embedded in a copper stabilizer, was used as a conductor sample. The measurement results

Remote Sensing Satellites use IR (Infra-Red) detectors for imaging in 1 um to 15 um bands. Most of these detectors are operated at cryogenic temperatures to extract the low-level signal from the background noise. Stirling cycle based miniature active linear cryocoolers are now being widely used for cooling these IR detectors to cryogenic temperatures. The Cryocooler Control Electronics (CCE) used for

Superconducting magnet is a key component in magnetic resonance imaging (MRI). In general, vacuum pressure impregnation (VPI) technology is used for insulating system of the superconducting magnet. Performance of the superconducting magnets is affected by the adhesion strength between superconducting wires and resins at cryogenic temperature. In this study, experimental superconducting coil was prepared

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

Magneto-thermal properties and magnetocaloric effect of ErFe2 have been studied. Molecular field theory has been applied on ErFe2 to calculate the magnetization and the magnetic contribution to the heat capacity and entropy. Our calculation shows that ErFe2 is a ferrimagnetic compound with a compensation temperature of around 475 K and a Curie temperature of 596 K. Applying magnetic field to ErFe2

Cryogenic system working at 2 K is crucial for superconducting accelerator. A 70 W@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

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

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

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 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

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

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

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

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 cause

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

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

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

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

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