Pub Date : 2025-10-25DOI: 10.1016/j.cryogenics.2025.104221
Hye-In Kim , Bong-Geon Chae , Hyun-Ung Oh
Spaceborne cryogenic coolers generate undesirable micro-vibrations and excessive heat during on-orbit operations. Therefore, appropriate vibration isolators and thermal designs are required to ensure optimal cooling performance, mission lifetime, and vibration stability. In this study, we propose a thermal design strategy using graphite sheets with low stiffness and high thermal conductivity to enhance both the thermal control and vibration isolation performance of cryogenic coolers. The cooler assembly was optimized using Veritrek software, an advanced design optimization software based on a reduced-order model (ROM), to determine the optimal number of graphite sheet layers, radiator area, and thickness that meet the allowable temperature requirements of the cooler. In addition, free-vibration test was performed to verify the basic characteristics of the cooler assembly. The micro-vibration isolation performance of the applied graphite sheets was validated through micro-vibration test under a gravity offloading conditions.
{"title":"Veritrek-based thermal design and validation of spaceborne cooler micro-vibration isolation system combined with graphite sheets and vibration isolators","authors":"Hye-In Kim , Bong-Geon Chae , Hyun-Ung Oh","doi":"10.1016/j.cryogenics.2025.104221","DOIUrl":"10.1016/j.cryogenics.2025.104221","url":null,"abstract":"<div><div>Spaceborne cryogenic coolers generate undesirable micro-vibrations and excessive heat during on-orbit operations. Therefore, appropriate vibration isolators and thermal designs are required to ensure optimal cooling performance, mission lifetime, and vibration stability. In this study, we propose a thermal design strategy using graphite sheets with low stiffness and high thermal conductivity to enhance both the thermal control and vibration isolation performance of cryogenic coolers. The cooler assembly was optimized using Veritrek software, an advanced design optimization software based on a reduced-order model (ROM), to determine the optimal number of graphite sheet layers, radiator area, and thickness that meet the allowable temperature requirements of the cooler. In addition, free-vibration test was performed to verify the basic characteristics of the cooler assembly. The micro-vibration isolation performance of the applied graphite sheets was validated through micro-vibration test under a gravity offloading conditions.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"152 ","pages":"Article 104221"},"PeriodicalIF":2.1,"publicationDate":"2025-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145412664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper reports the development and the successful testing of the first operational high-temperature superconductor (HTS) magnet cooled with a single two-stage cryocooler using two cryogenic pulsating heat pipes (PHP) as thermal links. The superconducting magnet is a metal-as-insulation (MI) REBCO double-pancake “10 T class magnet” built in-house and was operated at neon temperature (around 30 K). The superconducting magnet, the current leads, the cryogenic cooling system and scheme, the pulsating heat pipes and the overall experimental facility are detailed in length. The operational working limit, quench, alternating current (AC) losses and heat dissipation evaluations as well as constant current stability tests were performed and are methodically discussed. A maximum magnetic field of 4.24 T was reached during ramp-up, while a field of 1.72 T was maintained in direct current (DC) conditions for more than six hours with the neon PHPs evidently active. Numerous tests have verified that the cryogenic system, which includes the cryocooler, PHPs, thermal links and power regulation system, is sufficiently dynamic to cope with the transient heat generated by the superconducting magnet. The AC tests demonstrated that this test setup, with the aid of cryogenic PHPs and its power regulation system, can serve as an evaluation tool for power dissipation due to AC losses.
{"title":"A HTS-MI magnet cooled by neon pulsating heat pipes system","authors":"Tisha Dixit, Thibault Lecrevisse, Gilles Authelet, Matthias Durochat, Vadim Stepanov, Emeric Benoist, Antomne Caunes, Théophile Benoit, Bruno Maloeuvre, Edouard Pepinter, Philippe Fazilleau, Bertrand Baudouy","doi":"10.1016/j.cryogenics.2025.104214","DOIUrl":"10.1016/j.cryogenics.2025.104214","url":null,"abstract":"<div><div>This paper reports the development and the successful testing of the first operational high-temperature superconductor (HTS) magnet cooled with a single two-stage cryocooler using two cryogenic pulsating heat pipes (PHP) as thermal links. The superconducting magnet is a metal-as-insulation (MI) REBCO double-pancake “10 T class magnet” built in-house and was operated at neon temperature (around 30 K). The superconducting magnet, the current leads, the cryogenic cooling system and scheme, the pulsating heat pipes and the overall experimental facility are detailed in length. The operational working limit, quench, alternating current (AC) losses and heat dissipation evaluations as well as constant current stability tests were performed and are methodically discussed. A maximum magnetic field of 4.24 T was reached during ramp-up, while a field of 1.72 T was maintained in direct current (DC) conditions for more than six hours with the neon PHPs evidently active. Numerous tests have verified that the cryogenic system, which includes the cryocooler, PHPs, thermal links and power regulation system, is sufficiently dynamic to cope with the transient heat generated by the superconducting magnet. The AC tests demonstrated that this test setup, with the aid of cryogenic PHPs and its power regulation system, can serve as an evaluation tool for power dissipation due to AC losses.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"152 ","pages":"Article 104214"},"PeriodicalIF":2.1,"publicationDate":"2025-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145412665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-24DOI: 10.1016/j.cryogenics.2025.104220
Jiarun Zou , Zijie Pan , Lingjiao Wei , Haowen Guo , Ruixin Li , Tuo Zang , Zhizhuo Zhang , Houlei Chen , Miguang Zhao , Jingtao Liang
Space exploration missions such as the DIXE require ultra-low temperature environments of around 100 mK to ensure high sensitivity operation of the detectors. Dilution refrigeration, as one of the few ultra-low temperature technologies, has been firstly applied in the Planck satellite with a cooling power of 100 nW@100 mK. To cope with the need for higher cooling capacity of the future space exploration missions, a dilution unit with the capillary structure for higher-flow-rate conditions is designed and tested in this work. The mechanism of the cooling start-up process from 1 K and the corresponding phase interface migration are analyzed through the temperature changes of different stages of the dilution unit. The no-load temperature can reach 81.4 mK, and the cooling capacity is 1.2 μW@100 mK. In addition, the working characteristics of the designed dilution unit are experimentally investigated.
{"title":"Design and experimental performance of a high-capacity space dilution refrigeration unit","authors":"Jiarun Zou , Zijie Pan , Lingjiao Wei , Haowen Guo , Ruixin Li , Tuo Zang , Zhizhuo Zhang , Houlei Chen , Miguang Zhao , Jingtao Liang","doi":"10.1016/j.cryogenics.2025.104220","DOIUrl":"10.1016/j.cryogenics.2025.104220","url":null,"abstract":"<div><div>Space exploration missions such as the DIXE require ultra-low temperature environments of around 100 mK to ensure high sensitivity operation of the detectors. Dilution refrigeration, as one of the few ultra-low temperature technologies, has been firstly applied in the Planck satellite with a cooling power of 100 nW@100 mK. To cope with the need for higher cooling capacity of the future space exploration missions, a dilution unit with the capillary structure for higher-flow-rate conditions is designed and tested in this work. The mechanism of the cooling start-up process from 1 K and the corresponding phase interface migration are analyzed through the temperature changes of different stages of the dilution unit. The no-load temperature can reach 81.4 mK, and the cooling capacity is 1.2 μW@100 mK. In addition, the working characteristics of the designed dilution unit are experimentally investigated.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"152 ","pages":"Article 104220"},"PeriodicalIF":2.1,"publicationDate":"2025-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145412662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-22DOI: 10.1016/j.cryogenics.2025.104217
Zhihang Zhang , Zhengze Chang , Changcheng Ma , Yi Huo , Rui Ge
The cryogenic neon turboexpander (CNTE) serves as the core component of the neon Claude cycle refrigerator. A comprehensive understanding of its internal flow loss mechanisms is critical for further enhancing CNTE performance. This study employs computational fluid dynamics (CFD) simulations coupled with entropy production analysis to investigate the flow behavior and energy dissipation mechanisms within the CNTE. The numerical results demonstrate that approximately 91.5 % of the total entropy production originates from the impeller and diffuser components, and the primary loss mechanism stems from turbulent energy dissipation occurring at the interface of tip clearance leakage flow and the mainstream. Quantitative analysis reveals that expanding the tip clearance from 0 mm to 0.6 mm results in an 11.13 % deterioration in isentropic efficiency, accompanied by a corresponding 9.25 % reduction in cooling power. Furthermore, under asymmetric tip clearance conditions, changes in radial clearance have a much greater impact on the performance of CNTE than modifications to axial clearance. Additionally, rotational speed significantly impacts turboexpander performance, with an optimal rotational speed range existing to maximize both isentropic efficiency and cooling power. In summary, this study provides novel insights and a theoretical foundation for optimizing the operational parameters and structural design of cryogenic neon turboexpanders.
{"title":"Energy loss analysis of cryogenic neon turboexpander based on entropy production theory","authors":"Zhihang Zhang , Zhengze Chang , Changcheng Ma , Yi Huo , Rui Ge","doi":"10.1016/j.cryogenics.2025.104217","DOIUrl":"10.1016/j.cryogenics.2025.104217","url":null,"abstract":"<div><div>The cryogenic neon turboexpander (CNTE) serves as the core component of the neon Claude cycle refrigerator. A comprehensive understanding of its internal flow loss mechanisms is critical for further enhancing CNTE performance. This study employs computational fluid dynamics (CFD) simulations coupled with entropy production analysis to investigate the flow behavior and energy dissipation mechanisms within the CNTE. The numerical results demonstrate that approximately 91.5 % of the total entropy production originates from the impeller and diffuser components, and the primary loss mechanism stems from turbulent energy dissipation occurring at the interface of tip clearance leakage flow and the mainstream. Quantitative analysis reveals that expanding the tip clearance from 0 mm to 0.6 mm results in an 11.13 % deterioration in isentropic efficiency, accompanied by a corresponding 9.25 % reduction in cooling power. Furthermore, under asymmetric tip clearance conditions, changes in radial clearance have a much greater impact on the performance of CNTE than modifications to axial clearance. Additionally, rotational speed significantly impacts turboexpander performance, with an optimal rotational speed range existing to maximize both isentropic efficiency and cooling power. In summary, this study provides novel insights and a theoretical foundation for optimizing the operational parameters and structural design of cryogenic neon turboexpanders.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"152 ","pages":"Article 104217"},"PeriodicalIF":2.1,"publicationDate":"2025-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145412661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-22DOI: 10.1016/j.cryogenics.2025.104218
Haojian Su , Zekun Wang , Liancheng Xie , Mingyue Jiang
Full-lifecycle health monitoring of extreme low-temperature equipment heavily depends on the stability of the cryogenic mechanical behavior of core structural materials. Notably, Fe-Mn-C series high-manganese steels stand as key candidate material for extreme low-temperature scenarios at 4.2 K. To address three critical challenges for this material system—i.e., the lack of 4.2 K constitutive models, multi-scale modeling bottlenecks, and insufficient local monitoring—that directly limit its health monitoring, this study targets Fe-22 wt% Mn-1 wt% C-0.3 wt% Cu high-manganese austenitic steel to systematically investigate its 4.2 K constitutive behavior and microscale deformation mechanisms. The results are as follows: (1) At 4.2 K, the material exhibits a serrated stress–strain response in the plastic stage, characterized by “variable period, amplitude, and equilibrium position”; this behavior is dominated by the synergy of low-frequency (<60 Hz) dynamic strain aging (DSA) and mechanical twinning. (2) 4.2 K-adapted cryogenic digital image correlation (DIC) technology reveals that the material exhibits differentiated strain distributions across temperature ranges, providing direct visual evidence for risk zone localization in health monitoring. (3) Microscopic characterization confirms that the hierarchical twin structure at 4.2 K is the core mechanism sustaining the material’s strength-plasticity balance; based on this, a correlation model linking “macroscopic strain distribution and microscopic twin evolution” is established. Leveraging these results, this study establishes a foundational 4.2 K constitutive model incorporating DSA-twinning coupling terms. This model enables quantitative support for “stress-strain-failure risk” analysis in extreme low-temperature equipment health monitoring, facilitating the advancement of monitoring systems from “macroscopic evaluation” to “precision early warning”.
{"title":"Research on health monitoring of extreme low-temperature equipment","authors":"Haojian Su , Zekun Wang , Liancheng Xie , Mingyue Jiang","doi":"10.1016/j.cryogenics.2025.104218","DOIUrl":"10.1016/j.cryogenics.2025.104218","url":null,"abstract":"<div><div>Full-lifecycle health monitoring of extreme low-temperature equipment heavily depends on the stability of the cryogenic mechanical behavior of core structural materials. Notably, Fe-Mn-C series high-manganese steels stand as key candidate material for extreme low-temperature scenarios at 4.2 K. To address three critical challenges for this material system—i.e., the lack of 4.2 K constitutive models, multi-scale modeling bottlenecks, and insufficient local monitoring—that directly limit its health monitoring, this study targets Fe-22 wt% Mn-1 wt% C-0.3 wt% Cu high-manganese austenitic steel to systematically investigate its 4.2 K constitutive behavior and microscale deformation mechanisms. The results are as follows: (1) At 4.2 K, the material exhibits a serrated stress–strain response in the plastic stage, characterized by “variable period, amplitude, and equilibrium position”; this behavior is dominated by the synergy of low-frequency (<60 Hz) dynamic strain aging (DSA) and mechanical twinning. (2) 4.2 K-adapted cryogenic digital image correlation (DIC) technology reveals that the material exhibits differentiated strain distributions across temperature ranges, providing direct visual evidence for risk zone localization in health monitoring. (3) Microscopic characterization confirms that the hierarchical twin structure at 4.2 K is the core mechanism sustaining the material’s strength-plasticity balance; based on this, a correlation model linking “macroscopic strain distribution and microscopic twin evolution” is established. Leveraging these results, this study establishes a foundational 4.2 K constitutive model incorporating DSA-twinning coupling terms. This model enables quantitative support for “stress-strain-failure risk” analysis in extreme low-temperature equipment health monitoring, facilitating the advancement of monitoring systems from “macroscopic evaluation” to “precision early warning”.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"152 ","pages":"Article 104218"},"PeriodicalIF":2.1,"publicationDate":"2025-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-19DOI: 10.1016/j.cryogenics.2025.104215
Tiantian Xiao , Yi Liao , Xuming Liu , Changzhao Pan
The Knudsen pump, which operates based on the thermal transpiration effect and contains no moving parts, offers a promising solution for microfluidic transport. Its ability to function at low temperatures is particularly advantageous for applications such as hydrogen transportation, which help mitigate leakage risks, and space cryogenic systems, which require high reliability and compact design. This paper develops a numerical model of the low-temperature-driven Knudsen pump (LT-KP) based on the Navier-Stokes equations, incorporating velocity slip and temperature jump boundary conditions. The model simulates and evaluates the pressurization performance and the internal gas flow characteristics of the Knudsen pump over a temperature range extending from liquid nitrogen to room temperature. The simulation results indicate that a single-stage LT-KP can achieve a compression ratio of 1.02 under a temperature gradient of 223 K and an initial pressure of 1 atm. The study further investigates the impact of structural and operational parameters, including the number of stages, temperature gradients, gas rarefaction degree, microchannel dimensions, and gas types. More importantly, a design scheme for a closed-cycle dilution refrigerator incorporating LT-KP is proposed. The simulation results demonstrate that the 10-stage LT-KP, driven by the cascaded temperature gradients of 4 K-40 K and 40 K-300 K, can achieve pressurization from 5 mbar to 200 mbar. This research addresses the knowledge gap regarding Knudsen pump operation in cryogenic environments and provides valuable guidance for its application in refrigeration systems.
{"title":"Numerical investigation of the performance and gas flow characteristics of a novel low-temperature-driven multistage Knudsen pump","authors":"Tiantian Xiao , Yi Liao , Xuming Liu , Changzhao Pan","doi":"10.1016/j.cryogenics.2025.104215","DOIUrl":"10.1016/j.cryogenics.2025.104215","url":null,"abstract":"<div><div>The Knudsen pump, which operates based on the thermal transpiration effect and contains no moving parts, offers a promising solution for microfluidic transport. Its ability to function at low temperatures is particularly advantageous for applications such as hydrogen transportation, which help mitigate leakage risks, and space cryogenic systems, which require high reliability and compact design. This paper develops a numerical model of the low-temperature-driven Knudsen pump (LT-KP) based on the Navier-Stokes equations, incorporating velocity slip and temperature jump boundary conditions. The model simulates and evaluates the pressurization performance and the internal gas flow characteristics of the Knudsen pump over a temperature range extending from liquid nitrogen to room temperature. The simulation results indicate that a single-stage LT-KP can achieve a compression ratio of 1.02 under a temperature gradient of 223 K and an initial pressure of 1 atm. The study further investigates the impact of structural and operational parameters, including the number of stages, temperature gradients, gas rarefaction degree, microchannel dimensions, and gas types. More importantly, a design scheme for a closed-cycle dilution refrigerator incorporating LT-KP is proposed. The simulation results demonstrate that the 10-stage LT-KP, driven by the cascaded temperature gradients of 4 K-40 K and 40 K-300 K, can achieve pressurization from 5 mbar to 200 mbar. This research addresses the knowledge gap regarding Knudsen pump operation in cryogenic environments and provides valuable guidance for its application in refrigeration systems.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"152 ","pages":"Article 104215"},"PeriodicalIF":2.1,"publicationDate":"2025-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-17DOI: 10.1016/j.cryogenics.2025.104213
Jiulong Zhang , Zuoguang Li , Jingfeng Zhang , Zhiheng Ren , Jinhao Shi , Huan Jin , Jinggang Qin , Chao Zhou , Shaoqing Wei , Zhan Zhang
YBCO multi-filamentary tapes’ current-carrying performance is susceptible to torsional stress during cable and magnet fabrication. In this study, commercial YBCO tapes from Shanghai Superconductor Technology Co., Ltd. were cut using a reel-to-reel ultraviolet picosecond laser cutting device developed by our group to fabricate 2-filament, 6-filament, and 10-filament multi-filamentary tapes. Additionally, some of the multi-filamentary tapes were encapsulated using the copper-plating re-encapsulation process developed by our group. The current-carrying performance degradation behavior of non-striated tapes, unencapsulated multi-filamentary tapes, and re-encapsulated copper-plated multi-filamentary tapes under pure torsion mode was systematically analyzed. The results show that the degradation behavior of multi-filamentary tapes is strongly dependent on the number of filaments. Specifically, the critical current degradation rates of unencapsulated non-striated tapes and unencapsulated 2-filament tapes are 12.11 % and 12.43 % respectively when the shear strain reaches 0.4125 %. In contrast, unencapsulated 6-filament and unencapsulated 10-filament tapes exhibit degradation rates of 11.69 % and 20.96 % respectively at a lower strain (0.375 %). For samples subjected to single-side copper-plated re-encapsulation with a thickness of 10 μm, the pattern of performance degradation is essentially consistent with that of the samples before copper-plated re-encapsulation, but their overall ability to withstand shear strain is improved by approximately 0.1 %. Macroscopic observations indicate that the surface of the tapes remains smooth without delamination after torsion; however, the “triangular” deformation feature reveals uneven internal stress distribution, suggesting that the superconducting layer may have incurred microscopic damage..
{"title":"Study on the degradation of current-carrying performance of YBCO multi-filamentary tapes prepared by reel-to-reel ultraviolet picosecond laser cutting under pure torsion mode","authors":"Jiulong Zhang , Zuoguang Li , Jingfeng Zhang , Zhiheng Ren , Jinhao Shi , Huan Jin , Jinggang Qin , Chao Zhou , Shaoqing Wei , Zhan Zhang","doi":"10.1016/j.cryogenics.2025.104213","DOIUrl":"10.1016/j.cryogenics.2025.104213","url":null,"abstract":"<div><div>YBCO multi-filamentary tapes’ current-carrying performance is susceptible to torsional stress during cable and magnet fabrication. In this study, commercial YBCO tapes from Shanghai Superconductor Technology Co., Ltd. were cut using a reel-to-reel ultraviolet picosecond laser cutting device developed by our group to fabricate 2-filament, 6-filament, and 10-filament multi-filamentary tapes. Additionally, some of the multi-filamentary tapes were encapsulated using the copper-plating re-encapsulation process developed by our group. The current-carrying performance degradation behavior of non-striated tapes, unencapsulated multi-filamentary tapes, and re-encapsulated copper-plated multi-filamentary tapes under pure torsion mode was systematically analyzed. The results show that the degradation behavior of multi-filamentary tapes is strongly dependent on the number of filaments. Specifically, the critical current degradation rates of unencapsulated non-striated tapes and unencapsulated 2-filament tapes are 12.11 % and 12.43 % respectively when the shear strain reaches 0.4125 %. In contrast, unencapsulated 6-filament and unencapsulated 10-filament tapes exhibit degradation rates of 11.69 % and 20.96 % respectively at a lower strain (0.375 %). For samples subjected to single-side copper-plated re-encapsulation with a thickness of 10 μm, the pattern of performance degradation is essentially consistent with that of the samples before copper-plated re-encapsulation, but their overall ability to withstand shear strain is improved by approximately 0.1 %. Macroscopic observations indicate that the surface of the tapes remains smooth without delamination after torsion; however, the “triangular” deformation feature reveals uneven internal stress distribution, suggesting that the superconducting layer may have incurred microscopic damage..</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"152 ","pages":"Article 104213"},"PeriodicalIF":2.1,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-10DOI: 10.1016/j.cryogenics.2025.104211
Jinjie Wang , Qile Ren , Honggang Wen , Zuchao Zhu , Xiaojun Li
Cryogenic submerged pumps (CSPs) are imperative for the efficient transport of cryogenic fluids; however, their multi-stage energy conversion mechanisms remain insufficiently understood under extreme operating conditions. This study aims to quantitatively elucidate the internal flow field and energy transfer characteristics of a two-stage CSP by developing an energy conversion and loss analysis method based on power density distribution. This method integrates high-fidelity numerical simulations and experimental validation using liquid nitrogen. The results reveal that the first-stage impeller is highly sensitive to inlet flow disturbances under off-design conditions, with local flow separation increasing turbulence intensity and energy dissipation; the deviation proportion (DP) in certain channels exceeds 15%. Conversely, the second-stage impeller exhibits a more uniform power density distribution and maintains stable outlet pressure even at 1.4Qd, where its kinetic energy increment extends to a streamline distance of 0.36 compared to 0.2 in the first stage. Guide vanes account for 65 % of the total turbulent dissipation power and 59 % of wall friction loss, with peak kinetic-to-pressure energy conversion efficiency occurring at a streamline distance of 0.3. Both the impeller and guide vanes exhibit similar energy transfer processes: power density increases slightly at the inlet, decreases gradually along the channel, and rebounds near the outlet. These findings clarify inter-stage synergy and loss mechanisms while providing quantitative design guidance for optimising impeller–guide vane matching, thereby improving overall efficiency and expanding the high-efficiency operating range of multi-stage CSPs.
{"title":"Energy conversion and loss characteristics of multi-stage cryogenic submerged pumps based on power density evolution model","authors":"Jinjie Wang , Qile Ren , Honggang Wen , Zuchao Zhu , Xiaojun Li","doi":"10.1016/j.cryogenics.2025.104211","DOIUrl":"10.1016/j.cryogenics.2025.104211","url":null,"abstract":"<div><div>Cryogenic submerged pumps (CSPs) are imperative for the efficient transport of cryogenic fluids; however, their multi-stage energy conversion mechanisms remain insufficiently understood under extreme operating conditions. This study aims to quantitatively elucidate the internal flow field and energy transfer characteristics of a two-stage CSP by developing an energy conversion and loss analysis method based on power density distribution. This method integrates high-fidelity numerical simulations and experimental validation using liquid nitrogen. The results reveal that the first-stage impeller is highly sensitive to inlet flow disturbances under off-design conditions, with local flow separation increasing turbulence intensity and energy dissipation; the deviation proportion (<em>DP</em>) in certain channels exceeds 15%. Conversely, the second-stage impeller exhibits a more uniform power density distribution and maintains stable outlet pressure even at 1.4<em>Q</em><sub>d</sub>, where its kinetic energy increment extends to a streamline distance of 0.36 compared to 0.2 in the first stage. Guide vanes account for 65 % of the total turbulent dissipation power and 59 % of wall friction loss, with peak kinetic-to-pressure energy conversion efficiency occurring at a streamline distance of 0.3. Both the impeller and guide vanes exhibit similar energy transfer processes: power density increases slightly at the inlet, decreases gradually along the channel, and rebounds near the outlet. These findings clarify inter-stage synergy and loss mechanisms while providing quantitative design guidance for optimising impeller–guide vane matching, thereby improving overall efficiency and expanding the high-efficiency operating range of multi-stage CSPs.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"152 ","pages":"Article 104211"},"PeriodicalIF":2.1,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145320836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-06DOI: 10.1016/j.cryogenics.2025.104212
Rock Kil Ko, Hyun Woo Noh, Tae Hyung Koo, Dong Woo Ha, Young Min Seo
In this study, we investigated the influence of hole pattern on the quench propagation behavior of high-temperature superconducting (HTS) wires utilizing a metal stitching technique. A nano-second laser processing system was used to fabricate precise micro-hole patterns through the metal and insulation layers of the HTS conductor. To evaluate the quench performance, HTS wires were prepared with various hole spacing patterns (5 cm, 2.5 cm, and 1 cm) and compared with an unmodified original wire. The results showed that as the hole spacing decreased, the decay of the central magnetic field after quench became significantly faster. In particular, the sample with 2.5 cm spacing exhibited a sharp drop in central field from 44 G to 3 G after quench. Additionally, a metal-insulated coil incorporating a 2 cm-spacing metal stitching pattern demonstrated a magnetic flux density decay rate exceeding 40 G/sec, indicating improved responsiveness in quench detection and protection systems. These findings confirm the potential of metal stitching as a structural strategy to enhance the quench safety in HTS applications.
{"title":"Effect of hole pattern on high temperature superconducting wire using metal stitching for high-speed quench propagation","authors":"Rock Kil Ko, Hyun Woo Noh, Tae Hyung Koo, Dong Woo Ha, Young Min Seo","doi":"10.1016/j.cryogenics.2025.104212","DOIUrl":"10.1016/j.cryogenics.2025.104212","url":null,"abstract":"<div><div>In this study, we investigated the influence of hole pattern on the quench propagation behavior of high-temperature superconducting (HTS) wires utilizing a metal stitching technique. A nano-second laser processing system was used to fabricate precise micro-hole patterns through the metal and insulation layers of the HTS conductor. To evaluate the quench performance, HTS wires were prepared with various hole spacing patterns (5 cm, 2.5 cm, and 1 cm) and compared with an unmodified original wire. The results showed that as the hole spacing decreased, the decay of the central magnetic field after quench became significantly faster. In particular, the sample with 2.5 cm spacing exhibited a sharp drop in central field from 44 G to 3 G after quench. Additionally, a metal-insulated coil incorporating a 2 cm-spacing metal stitching pattern demonstrated a magnetic flux density decay rate exceeding 40 G/sec, indicating improved responsiveness in quench detection and protection systems. These findings confirm the potential of metal stitching as a structural strategy to enhance the quench safety in HTS applications.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"152 ","pages":"Article 104212"},"PeriodicalIF":2.1,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145263217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-04DOI: 10.1016/j.cryogenics.2025.104210
Olga Kartuzova , Mohammad Kassemi , Daniel Hauser
Accurate prediction of cryogenic tank self-pressurization is critical for NASA’s short- and long-duration missions, where heat leakage into storage systems occurs through insulation, structural supports, and penetrations. To address this need, a two-phase CFD model was developed to simulate the self-pressurization of a cryogenic storage tank partially filled with liquid hydrogen. The model employed the Volume-Of-Fluid (VOF) approach to capture two-phase flow behavior, incorporating interfacial heat, mass and momentum transfer between the liquid and vapor phases. Validation was carried out against self-pressurization experiments performed using the K-site flightweight hydrogen storage tank at NASA Glenn Research Center. Initial validation focused on a 49 % liquid fill level followed by extension to additional fill levels of 29 % and 83 %, studied in the experiment. Laminar and turbulent simulations were performed, along with conjugate heat transfer, to evaluate pressurization dynamics across different operating conditions. Numerical results for tank pressures and fluid temperature are compared with experimental data under external tank heat fluxes of 3.5 and 2.0 W/m2. The effects of turbulence modeling, liquid fill level, and localized heat leaks through instrumentation penetrations are analyzed and discussed in detail.
{"title":"CFD validation of k-site tank self-pressurization under varying fill levels and heat fluxes with different turbulence models","authors":"Olga Kartuzova , Mohammad Kassemi , Daniel Hauser","doi":"10.1016/j.cryogenics.2025.104210","DOIUrl":"10.1016/j.cryogenics.2025.104210","url":null,"abstract":"<div><div>Accurate prediction of cryogenic tank self-pressurization is critical for NASA’s short- and long-duration missions, where heat leakage into storage systems occurs through insulation, structural supports, and penetrations. To address this need, a two-phase CFD model was developed to simulate the self-pressurization of a cryogenic storage tank partially filled with liquid hydrogen. The model employed the Volume-Of-Fluid (VOF) approach to capture two-phase flow behavior, incorporating interfacial heat, mass and momentum transfer between the liquid and vapor phases. Validation was carried out against self-pressurization experiments performed using the K-site flightweight hydrogen storage tank at NASA Glenn Research Center. Initial validation focused on a 49 % liquid fill level followed by extension to additional fill levels of 29 % and 83 %, studied in the experiment. Laminar and turbulent simulations were performed, along with conjugate heat transfer, to evaluate pressurization dynamics across different operating conditions. Numerical results for tank pressures and fluid temperature are compared with experimental data under external tank heat fluxes of 3.5 and 2.0 W/m<sup>2</sup>. The effects of turbulence modeling, liquid fill level, and localized heat leaks through instrumentation penetrations are analyzed and discussed in detail.</div></div>","PeriodicalId":10812,"journal":{"name":"Cryogenics","volume":"152 ","pages":"Article 104210"},"PeriodicalIF":2.1,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145263286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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