bluuebunny/crossref_metadata_2025_split huggingface dataset:
Architectural impacts of in-situ resource utilization production of oxygen for use as propellant in a Mars ascent vehicle
Authors: Krenn A , Trent D , Sanders G , Hoffman S , Chai P , Hinterman E 
Published: June 2022

Abstract
NASA is in the processes of evaluating various architectures that may support human missions to Mars. A multitude of concepts are being traded and associated sensitivities are being analyzed. Among these trades, several options for Mars Ascent Vehicle (MAV) propellant supply are being considered. Due to mass constraints on the Mars descent system and the in-space transportation system, landing a fully fueled MAV, that can launch humans from the surface of Mars, presents significant integrated architecture challenges. Consequently, MAV propellant must either be pre-positioned and transferred across the surface robotically or made on the surface via In-Situ Resource Utilization (ISRU) techniques. In each case, there are implications to the number of architecture elements, total system mass, power requirements, complexity of operations, and required technology developments. An analysis that compares an ISRU point solution to a similar point solution that pre-positions and transfers propellant is detailed.
Development of a surface cryogenic propellant transfer concept for Martian operations
Authors: Congiardo J , Krenn A , Martinez J , Dupuis M , Swanger A 
Published: June 2022

Abstract
NASA is currently evaluating architectures to support human missions to Mars. A multitude of concepts are being traded and associated sensitivities are being analyzed. Mars Ascent Vehicle (MAV) propellant supply is a key consideration. Mass constraints for the Mars descent system and in-space transportation present significant architectural challenges that may preclude landing a fully fueled MAV for crew use. In such a case, to ensure the ability of the crewed mission to meet its objectives, propellant should be supplied to the MAV prior to the arrival of the crewed mission from Earth. A concept to robotically transfer liquid oxygen from a separate storage tanker across the surface to the MAV is proposed. This concept makes use of an unpressurized rover and is optimized to maximize the amount of propellant conveyed per trip.
Three-dimensional fluid-structural interaction and thermal analysis of a large diameter horizontal cryogenic transfer line
Authors: Lohar Kailash , Raj Kunniyoor Keerthi , Ventateshwaran K.S. , Ghosh Parthasarathi 
Published: June 2022

Abstract
This paper focuses on the thermal stress analysis and the thermal bowing phenomenon in a large 12-inch diameter cryogenic transfer line during chill-down with liquid oxygen. To investigate the chill-down characteristics and corresponding thermal stress generation, a threedimensional fluid-structural numerical model has been adopted in this work. The numerical simulation is performed on a 2 m long transfer line having an internal diameter of 30.48 cm (12 inch). Three dimensional modelling has been performed to numerate the channel wall temperature distribution along with the flow, at the top and the bottom portions. Based on the temperature data from CFD calculations, transient structural analysis and deformation of the transfer line are studied using a finite element model. Results show that the bowing in the transfer line occurs when there is a strong circumferential variation in temperature. Furthermore, this study provides a numerical simulation that predicts the chill-down time and the time when a stratified flow occurs in the line. This numerical method has been found to be a useful tool for the evaluation, design, and development of a large diameter cryogenic transfer line for transportation of large quantity of cryogenic fluid.
Development of a 2∼4 K closed-cycle JT cryocooler for space application
Authors: Pan Xiaoshan , Liu Shaoshuai , Wu Yinong , Jiang Zhenhua , Ding Lei 
Published: June 2022

Abstract
Cryogenic system proving cooling capacity at liquid helium temperatures is one of the key technologies for space exploration missions. A closed-cycle Joule-Thomson cryocooler capacity of providing different cooling powers at 2∼4 K is developed in our lab. The cryocooler is precooled by a two-stage thermal coupled pulse-tube cryocooler with active phase shifter and driven by multi-stage valved linear compressors. The lowest temperature about 2.5 K and more than 50 mW at about 4.0 K can be obtained by adapting the suited charging pressures. The two-stage pulse tube cryocooler can provide pre-cooling capacity at 17 K and 76 K, respectively with an input power of about 350 W. A large pressure ratio of about 26 and a mass flow rate of 6.7 mg/s can be provide by the multi-stage valved linear compressors with a charge pressure of 0.6 MPa and a total electrical power of less than 110 W. The cooling-down time for the cryocooler from room temperature to about 4 K is less than 10 hours. The cooling system can provide a required cryogenic environment for future space applications.
An 880 mW@15 K thermal coupled pulse tube cryocooler with active phase shifter
Authors: Yin Wang , Liu Shaoshuai , Wu Yinong , Jiang Zhenhua , Ding Lei , Song Jiantang 
Published: June 2022

Abstract
A two-stage Stirling-type pulse tube cryocooler (SPTC) operating in 15 K is developed in our lab for cooling infrared detectors and precooling helium JT cryocooler. For easy adjustment, the driven compressor of the SPTC is designed as two independent linear compressors. The second stage cold finger uses an active warm displacer (AWD) as phase shifter to maximize the cooling performance. The variation of pre-cooling temperature and swept volume of the AWD will influence the cooling capacity of the SPTC. The cooling performance are experimentally tested and analyzed. With the pre-cooling temperature of 80 K, the second stage cold finger can obtain 470 mW at cooling temperature of 15 K with a total electric input power of 363 W. It can also obtain 880 mW at cooling temperature of 15 K with full input power of 527 W. A no-load temperature of 9.9 K can be obtained with an electric power of 180 W and 170 W for first and second stage. The experimental results also show that there exists an optimal pre-cooling temperature and swept volume of the AWD to achieve the maximum cooling capacity for 20 K applications.
Parasitic heat load in a miniature pulse tube cooler
Authors: Dherbecourt D , Duval J M , Garcia M , Lopes D , Guichard D , Branco M B C , Prouvé T 
Published: June 2022

Abstract
The parasitic heat load represents the heat flow disturbing the cold end of cryocoolers due to conduction, convection and radiation. On-board space missions, cryocoolers such as pulse tubes are typically employed in a cold redundancy scheme. Therefore, the heat flow through a pulse tube cooler in OFF state directly affects the cold performance of the operating cooler, bringing in heat and limiting the total available cooling power at the cold tip. The reference pulse tube is a miniature pulse tube cooler, developed for 2 W cooling at 80 K with a low input power. This study aims first to measure the parasitic heat load through three methods, which results are compared and confronted with numerical evaluation based on well-known correlations. Then a novel way in design is proposed, integrating an element of lower conduction replacing a part of the regenerator in order to reduce the heat load. The impact of this modification on the performance is measured and compared with its influence on the heat load.
Numerical analysis and experimental research of a 2W/35 K Stirling-type pulse tube cryocooler
Authors: Gao Z Z , Yang B , Chen L B , Wang J J 
Published: June 2022

Abstract
Cooling to the temperature of liquid nitrogen to liquid hydrogen is a necessary working prerequisite for some infrared detectors. The development of compact and efficient miniature cryocoolers is of great significance for the space application of the detectors. The pulse tube cryocooler driven by a dual-opposed linear compressor is prospective in space applications due to the advantages of no low-temperature moving parts, compact structure, and high reliability. In this paper, a 2W/35K Stirling-type pulse tube cryocooler with a single-stage structure has been designed and tested. The influences of structural parameters of the phase shifters such as inertance tube, as well as the operating parameters such as operating frequency and charging pressure, on the cooling performance were investigated through numerical calculations and experiments.
A thermal-coupled/gas-coupled hybrid high-frequency pulse tube cryocooler attaining the liquid-helium temperature
Authors: Yang Biao , Gao Zhaozhao , Xi Xiaotong , Chen Liubiao , Wang Junjie 
Published: June 2022

Abstract
High-frequency pulse tube cryocooler (HPTC) has become an attractive method for space cooling in the liquid-helium temperature range, due to its advantages of potential high efficiency, no moving parts at the cold end, small size, and light weight. However, key problems such as large regenerator losses and insufficient phase-shifting ability challenge it to obtain the liquid-helium temperature. A thermal-coupled/gas-coupled hybrid refrigeration process of HPTC has been designed to obtain the liquid-helium temperature. One HPTC working in the liquid-nitrogen temperature range is used as a pre-cooling stage, and another two-stage gas-coupled structure is employed to obtain liquid-helium temperature. The simulation results show that the lowest no-load temperature is 3.6 K and a cooling power of 84 mW can be provided at 6 K with a total input PV power of 128 W and 10.9 W/77 K pre-cooling power when Helium-4 is chosen as the working gas. An experimental prototype was designed, built, and tested. The simulation and experiment results will be introduced in detail in this paper.
Analysis of radiation energy between light source, optical window and cryogenic sample
Authors: Wu S S , Wang J , Zhang H C , Shen F Z , Huang C J , Li L F , Zhou Y 
Published: June 2022

AbstractThe cryogenic mechanical properties of materials are particularly important in cryogenic engineering fields. The digital image correlation technique is a method to measure strain and displacement with high precision without contact. The optical window is necessary for DIC technology to obtain the cryogenic mechanical properties of materials. However, the thermal radiation energy between the light source, the glass and the sample greatly affects the limit temperature of the cryogenic mechanical measurement. In this paper, the spectral radiation properties of the glass and sample surfaces for the wavelength of 0.38-25 μm were measured. The thermal radiation energy between the power density emitted by the light source, the radiation energy emitted by the glass surface and the radiation energy emitted by the sample were analyzed. Finally, the effects of illumination distances on the radiation energy density and the sample temperature were studied. The results indicate that the power density emitted by the light source accounts for the main part of the radiant energy density received by the sample, and the radiant energy on the glass and the sample surface are negligible. Moreover, increasing the illumination distance is effective to reduce the radiation energy and temperature rise of the sample.
Analysis of pump tube and orifice for a 4He sub-Kelvin sorption cooler
Authors: Lei Y L , Zhao Y N , Quan J , Hong G T 
Published: June 2022

Abstract
The sub-Kelvin sorption cooler (SKSC) has become one of the most significant refrigerators in the space sub-Kelvin temperature range due to its high reliability, long life, no interference, and portability. The refrigeration temperature of SKSC is determined by the saturated vapor pressure above the liquid working medium in the evaporator, which is not only related to the adsorption capacity of the adsorption compressor but may also be restricted by the flow resistance of the pump tube and the orifice (for 4He SKSC). In addition, the pump tube and the orifice will also affect the heat leakage of superfluid 4He and the heat insulation between the adsorption compressor and the evaporator. Therefore, when designing a 4He SKSC, the pump tube and the orifice are critical. In this paper, the above issues are comprehensively considered, and the allowable size range of the pump tube and the orifice under a given design condition is discussed.
Visualization study of a cryostat with a large diameter flow channel for flowing high-pressure cryogenic fluid
Authors: Xie S Y , Zhang Z Z , Xu D , Lyu B K , Li L F 
Published: June 2022

Abstract
For abundant cryogenic experiments, systems, and so on, visualization is necessary to observe the cryogenic fluid. Therefore, the visualization methods of cryogenic fluid have been widely studied, such as shadowgraph technique, schlieren technique, and laser holographic interferometry technique. A cryostat for visualization study must have optical windows to meet the requirement of various image acquisition equipment. Due to the difference of shrinkage between transparent glass and device materials at low temperatures, especially at large diameter flow channels, it is difficult to meet the requirement of visualization. This paper studies a kind of cryogenic visualization device with an inner diameter of 200 mm, which can meet the visualization requirements of cryogenic fluid with the maximum working pressure at 0.7 MPa and the lowest temperature at 77 K. Liquid nitrogen was used to test the visualization of the device at low temperatures. The device was also subjected to vibration conditions to test the ability of the device to withstand harsh environments. The results show that the device has good sealing performance and can meet the visualization requirements well.
An innovative approach for the design of cryogenic electrical and process control systems at CERN: the cryogenic Continuous Integration project
Authors: Barbe T , Pezzetti M , Martin S , Tovar-Gonzalez A , Fluder C , Wolak T 
Published: June 2022

Abstract
Designing, building, commissioning, operating and maintaining multiple complex cryogenics process control systems involves many challenges. For several years, CERN has developed various solutions to help with the whole lifecycle of a cryogenic process control system. This has allowed the production of quality and highly reliable cryogenic control and electrical systems. This paper will present the use of these innovative and automated tools and their evolution; focusing in the first part on continuous integration practices applied to the production of Programmable Logic Controller (PLC) software. The second part will develop the practical applications for software upgrades implemented for the cryogenics processes of non-LHC detectors and test facilities at CERN. Finally, a detailed description of the approach to a standardized generation of electrical drawing for cryogenic systems will be presented along with concrete solutions already successfully implemented in operation.
In-flow measurement of the composition of a binary gas mixture
Authors: Tolboom A.H. , Vermeer C.H. , Holland H.J. , ter Brake H.J.M. 
Published: June 2022

Abstract
The performance of many cryocoolers that utilize the Joule-Thomson effect can be improved by using a gas-mixture as the working fluid. This paper presents a measurement setup to characterize a sorption compressor operating with a binary mixture. The composition of the binary mixture delivered by the sorption compressor is determined in-flow by correlating the outputs of a Coriolis flow meter and a thermal mass-flow meter. Based on this method, the composition of a binary mixture was measured continuously with an error of ±0.02. Multiple sorption cycles with three different mixtures of ethane and nitrogen using the same compressor were measured, allowing for the observation of the dynamic desorption behavior of a mixture.
Design of cryogenic test platform for the seal structure in superfluid helium temperature
Authors: Li Z , Zhou Z , Zhang Q , Wang G , Huang J 
Published: June 2022

Abstract
A cryogenic test platform was conceived and designed with a variable temperature from 1.8K to 300K to accomplish the research of cryogenic seal performance, and the main research object of this platform is to test the seal capacity of the flange structure in superfluid helium condition. This platform mainly includes a cryostat, a set of vacuum pumps, a sealed test chamber, a cryogenic physical property test chamber, a leak detection system, a superfluid helium acquisition system, and temperature control systems. The cold source is supplied by 1.5K superfluid helium, which will be obtained by combining throttling with decompression. Mechanical structure designs and detailed parameters of the entire platform will be presented in this paper.
Performance study of preloaded cryogenic bearings in liquid hydrogen pump
Authors: Su H , Lv C , Shang J , Huang B H , Feng Y , Wu J H 
Published: June 2022

Abstract
As a clean and efficient energy, liquid hydrogen has become an important solution for the energy restructuring in the future. The centrifugal liquid hydrogen pump has been applied in the storage, transportation and distribution of liquid hydrogen. As the support of pump rotor, the performance of cryogenic bearings are essential to the dynamic characteristics and design optimization of liquid hydrogen pump. In this paper, an improved quasi-static model for cryogenic bearing in liquid hydrogen pump was introduced, in which the effects of high-speed centrifugal expansion and shrinkage under cryogenic condition on bearing rings were considered. Based on this model, the effects of rotating speed and axial preload on bearing dynamic characteristics were studied. At the same time, the friction within the cryogenic bearing was analysed and calculated. Finally, the load variation of bearing preload disc spring at cryogenic temperature was calculated and experimentally studied. The results of this paper will provide theoretical suggestions for further engineering design and applications of cryogenic bearings in liquid hydrogen pump.
Stability analysis on gas-lubricated bearing for high speed cryogenic turbo-expander
Authors: Zheng L W , Zhang X H , Peng N , Yan H , Ke C L , Li K R , Liang Y W , Xiong L Y , Dong B , Li J , Liu I Q 
Published: June 2022

Abstract
Here, instead of using static characteristics of gas journal bearing such as the damping coefficients and the misalignment angle for stability analysis, a linear method is presented for studying the whirl stability of a rigid rotor supported on both cylindrical bearing and externally pressurized bearing. First, by using linearization method, the gas film forces can be represented as 8-coefficents, and they are calculated through perturbation method, the static performance is validated by published literature. Then, based on the Routh-Hurwitz criterion, the stability threshold is determined and graphically presented regarding several non-dimensional system parameters, which reflects the effects of both the eccentricity and supply pressure on the system’s linear stability. This effective and computationally cheap method of stability analysis is helpful for the prior design of gas bearing.
Design of Cryogenic Heat Exchangers and associated Sub-Systems for Controlled Cool-down and Testing of Superconducting Magnets at FRIB
Authors: Hasan N. , Ganni V. , Fila A. , Casagrande F. 
Published: June 2022

Abstract
The Facility for Rare Isotope Beams (FRIB) is a continuous wave heavy ion beam linear accelerator designed for a maximum beam energy of 400 kW and using in-flight (fragment) production and separation to generate rare isotope beams. Spatial separation of the isotopes is achieved by using superconducting magnets with a high magnetic field, large aperture, and iron-dominated core. There are a total of 14 superconducting magnets used in the fragment separator section of the facility. Designs for these magnets are relatively new, and it poses challenges in several aspects of the cryogenic design and operation such as, compact coil and cryostat design, thermal shield design, and a controlled cool-down to the operating temperature while avoiding high thermal stresses. Helically coiled finned-tube cryogenic heat exchanger designs are considered for the controlled cool-down of superconducting magnets with up to 22.4 tonnes of cold mass. These heat exchangers use liquid nitrogen cooled helium gas to cool the superconducting magnets. They demonstrate high thermal effectiveness and mechanical flexibility that are essential for the variable operating temperatures (300 – 80 K) experienced during a cool-down process. This paper presents an overview of the process design, analysis, fabrication and operation of cool-down heat exchangers and their associated sub-systems developed at FRIB.
Entropy optimization of an additively manufactured heat exchanger with a dual stage Gifford-McMahon cryogenic refrigerator for hydrogen liquefaction
Authors: Raymond J , Bunge C , Pesek L , Leachman J 
Published: June 2022

Abstract
Small-scale hydrogen liquefaction has emerged as an approach to fuel small aircraft powered by fuel cells. However, limited research on the design and optimization of small-scale hydrogen liquefiers, specifically the heat exchangers, is available. This paper describes a minimum entropy design for a heat exchanger mounted on a dual stage Gifford-McMahon cryogenic refrigerator. To minimize entropy generation the heat exchanger utilizes a bifurcating flow structure with varying wall thickness. Numerical optimization indicates that the heat exchanger will generate half of the entropy of a single coiled tube, significantly reducing the required heat exchanger length by 91.4% and the thermal mass by 43.8%. The heat exchanger was 3D printed with an aluminum alloy and the interior coated with a ruthenium-based catalyst for ortho-parahydrogen conversion. Hydrogen entering the heat exchanger near 293 K and 653 kPa is cooled to 28.1 K and full ortho-parahydrogen conversion is assumed before entering the storage dewar. The resulting experimental tests indicate a potential to increase heat exchanger efficiency in a more compact form factor, as well as a promising future for additively manufactured components in cryogenics.
Status of the PIP-II Cryoplant
Authors: Jia Y. , Hansen B. , Creus Prats J. , Atassi O. , Klebaner A. , Chakravarty A. , Goyal M. , Kumar J. 
Published: June 2022

Abstract
The Proton Improvement Plan-II (PIP-II) is an essential upgrade to the Fermilab accelerator complex featuring a new 800-MeV Superconducting Radio-Frequency (SRF) linear accelerator (Linac). The Linac contains 23 SRF cryomodules with the SRF cavities operating at 2 K, a high temperature thermal shield at 40 K and low temperature intercepts at 4.5 K. The PIP-II cryoplant will provide the necessary cooling for the cryomodules and the cryogenic distribution system interconnecting cryoplant and cryomodules. This paper describes the evolution of the PIP-II cryoplant conceptual design and specifications, including the expected heat loads, required cooling features and the integrated design. The cryoplant capacity margin analysis and fast cool-down mode will also be discussed.