Pub Date : 2024-05-01DOI: 10.1088/1757-899x/1309/1/011001
V-V Visuri, T. Echterhof
The European Academic Symposium on EAF Steelmaking (EASES) is a series of events targeted at researchers and doctoral candidates working with different aspects of electric arc furnace (EAF) steelmaking. Previously, four events were organised in 2015, 2016, 2018, and 2021 in Aachen, Germany. The 5th European Academic Symposium on EAF Steelmaking (EASES 2023) was organised jointly by the RWTH Aachen University (Department for Industrial Furnaces and Heat Engineering) and University of Oulu (Process Metallurgy Research Unit) and held at the University of Oulu in Oulu, Finland on 5-7 June 2023. A total of 29 presentations were held at the event, out of which 13 featured an accompanying full paper. After the symposium, the authors of the full papers were invited to submit their manuscripts to be included in the proceedings. The proceedings consist of a total of 12 peer-reviewed papers published in the IOP Conference Series: Materials Science and Engineering. Based on the presentations, the development of modelling and monitoring tools for process optimization, the use of biochar to replace fossil carbon for slag foaming, and the use of hydrogen as an alternative burner fuel were identified as current hot topics. In the future, the importance of the EAF process is expected to increase further due to the increasing availability of scrap and plans for ore-based production routes based on hydrogen direct reduction.
{"title":"Preface to the Proceedings of the 5th European Academic Symposium on EAF Steelmaking","authors":"V-V Visuri, T. Echterhof","doi":"10.1088/1757-899x/1309/1/011001","DOIUrl":"https://doi.org/10.1088/1757-899x/1309/1/011001","url":null,"abstract":"\u0000 The European Academic Symposium on EAF Steelmaking (EASES) is a series of events targeted at researchers and doctoral candidates working with different aspects of electric arc furnace (EAF) steelmaking. Previously, four events were organised in 2015, 2016, 2018, and 2021 in Aachen, Germany. The 5th European Academic Symposium on EAF Steelmaking (EASES 2023) was organised jointly by the RWTH Aachen University (Department for Industrial Furnaces and Heat Engineering) and University of Oulu (Process Metallurgy Research Unit) and held at the University of Oulu in Oulu, Finland on 5-7 June 2023. A total of 29 presentations were held at the event, out of which 13 featured an accompanying full paper. After the symposium, the authors of the full papers were invited to submit their manuscripts to be included in the proceedings. The proceedings consist of a total of 12 peer-reviewed papers published in the IOP Conference Series: Materials Science and Engineering. Based on the presentations, the development of modelling and monitoring tools for process optimization, the use of biochar to replace fossil carbon for slag foaming, and the use of hydrogen as an alternative burner fuel were identified as current hot topics. In the future, the importance of the EAF process is expected to increase further due to the increasing availability of scrap and plans for ore-based production routes based on hydrogen direct reduction.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"20 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141141032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-01DOI: 10.1088/1757-899x/1309/1/012004
M. Al Nasser, E. Karimi-Sibaki, M. Wu, C. Redl, A. Ishmurzin, N. Voller, G. Hackl, A. Kharicha
Electrovortex flow emerges when the current inside conducting liquids interacts with its self-induced magnetic field. The flow structure and strength of the flow are dictated by the current value and the presence of an external magnetic field. We present here 3D simulations for the electrovortex flow inside a liquid metal cylinder. The results presented reveal a typical electrovortex structure for low currents. Higher currents induce turbulence inside the electrovortex flow without any presence of an external magnetic field. In presence of Earth’s magnetic field, the flow structure is affected significantly. Cyclone, tornado, and rope tornado are observed inside the domain due to the earth’s magnetic field depending on the ratio of current applied and the earth’s magnetic field.
{"title":"3D Modelling of Electro Vortex Flow Inside Liquid Metal and Effect of External Magnetic Fields","authors":"M. Al Nasser, E. Karimi-Sibaki, M. Wu, C. Redl, A. Ishmurzin, N. Voller, G. Hackl, A. Kharicha","doi":"10.1088/1757-899x/1309/1/012004","DOIUrl":"https://doi.org/10.1088/1757-899x/1309/1/012004","url":null,"abstract":"\u0000 Electrovortex flow emerges when the current inside conducting liquids interacts with its self-induced magnetic field. The flow structure and strength of the flow are dictated by the current value and the presence of an external magnetic field. We present here 3D simulations for the electrovortex flow inside a liquid metal cylinder. The results presented reveal a typical electrovortex structure for low currents. Higher currents induce turbulence inside the electrovortex flow without any presence of an external magnetic field. In presence of Earth’s magnetic field, the flow structure is affected significantly. Cyclone, tornado, and rope tornado are observed inside the domain due to the earth’s magnetic field depending on the ratio of current applied and the earth’s magnetic field.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"34 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141135221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-01DOI: 10.1088/1757-899x/1306/1/012013
G Maiocchi, L Vigliano, G Nicoletto
The investigations here presented focus on the redesign and innovation of a pneumatic rack and pinion actuator for valve actuation, as a case study for investigating the potential of a multimethodology based on the Design to Value (DtoV) process, coupled with design techniques utilizing FEA simulations and giving high priority to teamwork. The final objective of this case study is to show how it is possible to optimize the design, increasing weight efficiency while maintaining performance, and to simplify it, with a reduction of components construction complexity, according to the growing demand for a lean production. The principle that guided all the activities was valorizing the power of teamwork, focusing the team on Safety and Reliability. In an initial phase, all the instruments foreseen by “Design-to-Value” process have been applied, obtaining a classification of the contents of the product constituting its sources of value. Subsequent outputs are proposals for efficient construction solutions, driving a second phase, dedicated to the re-design of the actuator. The peculiarity of this project has been to combine the “Design by Formulas” techniques with advanced FEA simulations (“Design by Analysis”), aiming to stress, deformation, and topology optimization. A two-step experimental validation is used, based on a preliminary “mockup” prototype followed by a complete detailed prototype, for confirming the results of the calculations and simulations, by directly performing a series of in-depth tests. Preliminary obtained results show that the approach based on the described multimethodology, makes it possible to optimize the design of the actuator, maintaining safety, reliability, and performance. In the case studied, the weight reduction is expected to be 8% and economic efficiency increase is expected to be near 20%.
{"title":"Multimethodology based on Design-to-Value (DtV), integrated with simulation techniques and prioritization of teamwork for the optimization of a pneumatic rack & pinion actuator","authors":"G Maiocchi, L Vigliano, G Nicoletto","doi":"10.1088/1757-899x/1306/1/012013","DOIUrl":"https://doi.org/10.1088/1757-899x/1306/1/012013","url":null,"abstract":"The investigations here presented focus on the redesign and innovation of a pneumatic rack and pinion actuator for valve actuation, as a case study for investigating the potential of a multimethodology based on the Design to Value (DtoV) process, coupled with design techniques utilizing FEA simulations and giving high priority to teamwork. The final objective of this case study is to show how it is possible to optimize the design, increasing weight efficiency while maintaining performance, and to simplify it, with a reduction of components construction complexity, according to the growing demand for a lean production. The principle that guided all the activities was valorizing the power of teamwork, focusing the team on Safety and Reliability. In an initial phase, all the instruments foreseen by “Design-to-Value” process have been applied, obtaining a classification of the contents of the product constituting its sources of value. Subsequent outputs are proposals for efficient construction solutions, driving a second phase, dedicated to the re-design of the actuator. The peculiarity of this project has been to combine the “Design by Formulas” techniques with advanced FEA simulations (“Design by Analysis”), aiming to stress, deformation, and topology optimization. A two-step experimental validation is used, based on a preliminary “mockup” prototype followed by a complete detailed prototype, for confirming the results of the calculations and simulations, by directly performing a series of in-depth tests. Preliminary obtained results show that the approach based on the described multimethodology, makes it possible to optimize the design of the actuator, maintaining safety, reliability, and performance. In the case studied, the weight reduction is expected to be 8% and economic efficiency increase is expected to be near 20%.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141193926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-01DOI: 10.1088/1757-899x/1306/1/012039
C Iandiorio, F Cafolla, E Marotta, P Salvini
Homogenization is a numerical technique to obtain the equivalent mediated response of a complex material. However, there are some scenarios in which the complexity of the physical phenomena present in the real structure makes it difficult to generate a faithful Representative Volume Element (RVE). In these cases, it may turn easier and more reliable to perform a homogenization directly by experimental test results. For this reason, we present a procedure to build-up the whole stiffness matrix starting from experiments. This approach is here discussed to get a homogenised two-node beam element. The procedure requires some flexibility measurements, thus allowing fewer measurements if compared to stiffness-based approach. The method is verified with some experiments carried on a frame structure. The comparisons with a Finite Element model build up with stiffness matrix assembly demonstrates the validity and robustness of the proposed procedure.
{"title":"Homogenized Stiffness Matrix of Two-Node Elements through Experimental Flexibility tests","authors":"C Iandiorio, F Cafolla, E Marotta, P Salvini","doi":"10.1088/1757-899x/1306/1/012039","DOIUrl":"https://doi.org/10.1088/1757-899x/1306/1/012039","url":null,"abstract":"Homogenization is a numerical technique to obtain the equivalent mediated response of a complex material. However, there are some scenarios in which the complexity of the physical phenomena present in the real structure makes it difficult to generate a faithful Representative Volume Element (RVE). In these cases, it may turn easier and more reliable to perform a homogenization directly by experimental test results. For this reason, we present a procedure to build-up the whole stiffness matrix starting from experiments. This approach is here discussed to get a homogenised two-node beam element. The procedure requires some flexibility measurements, thus allowing fewer measurements if compared to stiffness-based approach. The method is verified with some experiments carried on a frame structure. The comparisons with a Finite Element model build up with stiffness matrix assembly demonstrates the validity and robustness of the proposed procedure.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141193941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-01DOI: 10.1088/1757-899x/1306/1/012015
Massimiliano Palmieri, Alberto Ferri, Filippo Cianetti, Claudio Braccesi
Polymeric materials are widely used in several engineering sectors. Among these, a particularly critical sector for this type of material is that of roller coasters. The wheels are indeed made with an aluminum hub and a compact polyurethane coating, which, being in contact with the track, is subject to high speeds dynamic loads. Due to the viscoelastic behavior typical of these materials, such loads induce overheating of the coating and therefore a rapid degradation of the wheel. This results in machine downtime and, consequently, significant waste of time and money. In this context, the authors have developed a methodology for finite element thermo-structural analysis capable of quickly evaluating the temperature reached during work cycles and proving very useful in selecting the type of wheels to use. In this work, this methodology was firstly computationally developed and then validated by comparing the analysis results with data obtained from experimental tests conducted by the manifacturer. The comparison demonstrated the effectiveness of the proposed method, highlighting, however, a constant error in terms of maximum temperature reached attributable to a non-exact material characterization.
{"title":"Optimization and validation of a finite element methodology for thermo-structural analysis of polyhuretane wheels for roller coaster application","authors":"Massimiliano Palmieri, Alberto Ferri, Filippo Cianetti, Claudio Braccesi","doi":"10.1088/1757-899x/1306/1/012015","DOIUrl":"https://doi.org/10.1088/1757-899x/1306/1/012015","url":null,"abstract":"Polymeric materials are widely used in several engineering sectors. Among these, a particularly critical sector for this type of material is that of roller coasters. The wheels are indeed made with an aluminum hub and a compact polyurethane coating, which, being in contact with the track, is subject to high speeds dynamic loads. Due to the viscoelastic behavior typical of these materials, such loads induce overheating of the coating and therefore a rapid degradation of the wheel. This results in machine downtime and, consequently, significant waste of time and money. In this context, the authors have developed a methodology for finite element thermo-structural analysis capable of quickly evaluating the temperature reached during work cycles and proving very useful in selecting the type of wheels to use. In this work, this methodology was firstly computationally developed and then validated by comparing the analysis results with data obtained from experimental tests conducted by the manifacturer. The comparison demonstrated the effectiveness of the proposed method, highlighting, however, a constant error in terms of maximum temperature reached attributable to a non-exact material characterization.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141194040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-01DOI: 10.1088/1757-899x/1309/1/012010
E. Hoikkaniemi, P. Sulasalmi, V-V Visuri, T. Fabritius
Slag foaming practice is employed widely in electric arc furnace steelmaking to improve the energy efficiency, protect the furnace structures and reduce noise pollution. Slag foaming is typically launched by injecting fossil-based carbonaceous material (e.g. coke dust) into the melt. In this study, a novel laboratory-scale experimental setup was used for studying the substitution of fossil carbon by biochar as slag foaming agent. The setup was equipped with an injection device for feeding carbon and a camera system for observing the foaming phenomenon and recording the process. A set of experiments was conducted for studying the foaming in slag-carbon systems using two carbonaceous materials: 1) coke dust was used as a reference material and 2) a high-quality biochar was used as a possible replacement. In the experiments, sufficient foaming was achieved with both of the carbonaceous materials. The biochar produced almost equal foaming behavior as coke dust. The results indicate that biochar could be used to substitute carbon for slag foaming in the EAF.
{"title":"Biochar as a slag foaming agent in EAF – A novel experimental setup","authors":"E. Hoikkaniemi, P. Sulasalmi, V-V Visuri, T. Fabritius","doi":"10.1088/1757-899x/1309/1/012010","DOIUrl":"https://doi.org/10.1088/1757-899x/1309/1/012010","url":null,"abstract":"\u0000 Slag foaming practice is employed widely in electric arc furnace steelmaking to improve the energy efficiency, protect the furnace structures and reduce noise pollution. Slag foaming is typically launched by injecting fossil-based carbonaceous material (e.g. coke dust) into the melt. In this study, a novel laboratory-scale experimental setup was used for studying the substitution of fossil carbon by biochar as slag foaming agent. The setup was equipped with an injection device for feeding carbon and a camera system for observing the foaming phenomenon and recording the process. A set of experiments was conducted for studying the foaming in slag-carbon systems using two carbonaceous materials: 1) coke dust was used as a reference material and 2) a high-quality biochar was used as a possible replacement. In the experiments, sufficient foaming was achieved with both of the carbonaceous materials. The biochar produced almost equal foaming behavior as coke dust. The results indicate that biochar could be used to substitute carbon for slag foaming in the EAF.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"30 14","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141136438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-01DOI: 10.1088/1757-899x/1307/1/012047
B-A Behrens, S. Hübner, P. Müller, T. Fünfkirchler, J. Wehmeyer, K. Dilger, S. Hartwig, C. Gundlach
Multi-material structures in the automotive industry hold great potential for lightweight design, body construction, and functionalization due to their favorable mechanical properties and reduced structural weight. The combination of metal and plastic, in particular, is commonly used to enhance the overall properties of the end product when compared to single-material structures.This paper describes a process development with a hot-stamping and an extrusion tool. By means of this tool, a thermally assisted extrusion process can be used to join GMT (Glass Mat reinforced Thermoplastics) and 22MnB5 steel in a single process step. Through adhesion, the GMT adheres to the rough surface of the AlSi(aluminum-silicon)-coated 22MnB5. Test components were manufactured and through static tests the influence of process parameters was evaluated. Assuming that the parameters determined for the reference component are already sufficient for a design in the vehicle, the reduction of the steel thickness of the structure from 1.5 mm to 1.2 mm can be recommended on the basis of the results obtained. This is accompanied by a reduction in the mass of the test structure used while maintaining or improving its dynamic and static properties. Further weight savings appear possible through further component and process optimization.
{"title":"Reinforcement of thin hot-stamped components by fiber reinforced plastic structures with optimized fatigue strength properties","authors":"B-A Behrens, S. Hübner, P. Müller, T. Fünfkirchler, J. Wehmeyer, K. Dilger, S. Hartwig, C. Gundlach","doi":"10.1088/1757-899x/1307/1/012047","DOIUrl":"https://doi.org/10.1088/1757-899x/1307/1/012047","url":null,"abstract":"Multi-material structures in the automotive industry hold great potential for lightweight design, body construction, and functionalization due to their favorable mechanical properties and reduced structural weight. The combination of metal and plastic, in particular, is commonly used to enhance the overall properties of the end product when compared to single-material structures.This paper describes a process development with a hot-stamping and an extrusion tool. By means of this tool, a thermally assisted extrusion process can be used to join GMT (Glass Mat reinforced Thermoplastics) and 22MnB5 steel in a single process step. Through adhesion, the GMT adheres to the rough surface of the AlSi(aluminum-silicon)-coated 22MnB5. Test components were manufactured and through static tests the influence of process parameters was evaluated. Assuming that the parameters determined for the reference component are already sufficient for a design in the vehicle, the reduction of the steel thickness of the structure from 1.5 mm to 1.2 mm can be recommended on the basis of the results obtained. This is accompanied by a reduction in the mass of the test structure used while maintaining or improving its dynamic and static properties. Further weight savings appear possible through further component and process optimization.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141523430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-01DOI: 10.1088/1757-899x/1302/1/012016
Edgar R Canavan, Brian Comber
High reliability is an essential requirement for all spaceflight hardware. Like the Hitomi x-ray observatory, its follow-on mission XRISM uses 2G REBCO tapes as current leads for the superconducting magnets that are a key component of the Adiabatic Demagnetization Refrigerator (ADR) that cools the detector array. While the Hitomi Soft X-ray Spectrometer (SXS) worked flawlessly in orbit, during its development there were indications that the critical current of its specialized REBCO tapes could degrade over time when exposed to normal-humidity air. To demonstrate that the updates to the XRISM HTS lead assemblies had mitigated this risk, a series of tests were carried out to measure the stability of Ic of dozens of samples over a period greater than the flight assemblies were exposed to air during integration and test. The test rig allowed not only the measurement of the sample Ic, but also the localization of the voltage rise as the current approached Ic. We will discuss the trends in the critical current of the samples, as well as localization of lower Ic regions.
高可靠性是所有航天硬件的基本要求。与瞳 X 射线观测站一样，其后续任务 XRISM 也使用 2G REBCO 磁带作为超导磁体的电流导线，而超导磁体是绝热消磁制冷器（ADR）的关键部件，用于冷却探测器阵列。虽然 Hitomi 软 X 射线分光计（SXS）在轨道上的工作完美无瑕，但在其开发过程中，有迹象表明其专用 REBCO 磁带的临界电流在暴露于正常湿度的空气中时可能会随着时间的推移而降低。为了证明对 XRISM HTS 引线组件的更新已经降低了这一风险，我们进行了一系列测试，测量数十个样品在比飞行组件在集成和测试期间暴露在空气中的时间更长的时间内 Ic 的稳定性。测试设备不仅可以测量样品的 Ic，还可以在电流接近 Ic 时对电压上升进行定位。我们将讨论样品临界电流的趋势以及低 Ic 区域的定位。
{"title":"Critical current stability of 2G REBCO tape for space-flight HTS leads","authors":"Edgar R Canavan, Brian Comber","doi":"10.1088/1757-899x/1302/1/012016","DOIUrl":"https://doi.org/10.1088/1757-899x/1302/1/012016","url":null,"abstract":"High reliability is an essential requirement for all spaceflight hardware. Like the Hitomi x-ray observatory, its follow-on mission XRISM uses 2G REBCO tapes as current leads for the superconducting magnets that are a key component of the Adiabatic Demagnetization Refrigerator (ADR) that cools the detector array. While the Hitomi Soft X-ray Spectrometer (SXS) worked flawlessly in orbit, during its development there were indications that the critical current of its specialized REBCO tapes could degrade over time when exposed to normal-humidity air. To demonstrate that the updates to the XRISM HTS lead assemblies had mitigated this risk, a series of tests were carried out to measure the stability of <italic toggle=\"yes\">I<sub>c</sub>\u0000</italic> of dozens of samples over a period greater than the flight assemblies were exposed to air during integration and test. The test rig allowed not only the measurement of the sample <italic toggle=\"yes\">I<sub>c</sub>\u0000</italic>, but also the localization of the voltage rise as the current approached <italic toggle=\"yes\">I<sub>c</sub>\u0000</italic>. We will discuss the trends in the critical current of the samples, as well as localization of lower <italic toggle=\"yes\">I<sub>c</sub>\u0000</italic> regions.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141567291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-01DOI: 10.1088/1757-899x/1302/1/012009
Olivia-Ramona Bruj, Milan Majoros, Michael Sumption, Codrin-Gruie (CG) Cantemir
Optimization techniques can significantly improve the performance of electrical machines. The analysis and the optimization algorithms focus on computational efficiency. In this paper, the optimization of a high frequency electrical machine in cryogenic conditions is proposed. The losses introduced by AC current in a conductor are directly proportional with the applied frequency in terms of skin effect and proximity effect. The stator coil, made from two aluminium (Al) turns, in the presence of cryogenic coolants has been analysed at frequencies up to 1000 Hz. In order to reduce the AC losses introduced by the magnetic fields, Nonlinear Conjugate Gradient (NCG) method has been applied for the stator coil thickness optimization. Frequency dependence is observed in most simulations. In the presence of Liquid Hydrogen (LH2) coolant, Al 1100 conductor presents the minimum power loss.
{"title":"Tuned Windings: the window of opportunity for the implementation of solid conductors in high frequency cryogenic electric machines","authors":"Olivia-Ramona Bruj, Milan Majoros, Michael Sumption, Codrin-Gruie (CG) Cantemir","doi":"10.1088/1757-899x/1302/1/012009","DOIUrl":"https://doi.org/10.1088/1757-899x/1302/1/012009","url":null,"abstract":"Optimization techniques can significantly improve the performance of electrical machines. The analysis and the optimization algorithms focus on computational efficiency. In this paper, the optimization of a high frequency electrical machine in cryogenic conditions is proposed. The losses introduced by AC current in a conductor are directly proportional with the applied frequency in terms of skin effect and proximity effect. The stator coil, made from two aluminium (Al) turns, in the presence of cryogenic coolants has been analysed at frequencies up to 1000 Hz. In order to reduce the AC losses introduced by the magnetic fields, Nonlinear Conjugate Gradient (NCG) method has been applied for the stator coil thickness optimization. Frequency dependence is observed in most simulations. In the presence of Liquid Hydrogen (LH2) coolant, Al 1100 conductor presents the minimum power loss.","PeriodicalId":14483,"journal":{"name":"IOP Conference Series: Materials Science and Engineering","volume":"77 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141567301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-01DOI: 10.1088/1757-899x/1302/1/012010
L. Z. Deng, Z. Wu, T. Bontke, T. Habamahoro, D. Schulze, M. Gooch, T. W. Kuo, R. Fujikawa, C. W. Chu
This article will first briefly review the impressive advancements made in high-temperature superconductivity (HTS) before the arrival of room-temperature superconductivity (RTS). Accompanying the advancements made in superconductivity science and technology over the last century, a solid experimental framework concerning the search, development, and even authentication of new discoveries has been established. All these can serve as valuable references in the infancy of RTS research. In this spirit, we will comment on the current status of rare-earth hydride RTS and present our preliminary negative results on Lu-N-H and LK-99, the two most studied materials in the search for RTS in the last few months, although several more reports of negation than affirmation have appeared.
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