Pub Date : 2024-10-25DOI: 10.1109/JPHOTOV.2024.3478697
{"title":"IEEE Journal of Photovoltaics Information for Authors","authors":"","doi":"10.1109/JPHOTOV.2024.3478697","DOIUrl":"https://doi.org/10.1109/JPHOTOV.2024.3478697","url":null,"abstract":"","PeriodicalId":445,"journal":{"name":"IEEE Journal of Photovoltaics","volume":"14 6","pages":"C3-C3"},"PeriodicalIF":2.5,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10736236","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142518223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-24DOI: 10.1109/TPS.2024.3472696
N. Akhtar;S. Hussain
Ion-acoustic solitary waves in the negative ion plasmas in the presence of generalized (r, q) distributed electrons are studied. Equations of states for positive and negative ions are included in magnetized plasma. Reductive perturbation method (RPM) are applied to derive the Zakharov-Kuznetsov (ZK) equation. The impact of variation of spectral indices on propagation characteristic of ion acoustic solitary waves in negative ion plasma is discussed. The effect of negative ion temperature in the presence of generalized distribution of electrons is also presented. Our findings predict that equation of state of negative ions affects amplitude and width of the nonlinear solitary structure significantly. Our findings are applicable to laboratory as well as space plasmas where negative ion plasmas exist with magnetic field, and a flat-top feature for low-energy electrons and a high-energy tail in the distribution function of the electrons have been observed.
{"title":"The Impact of the Generalized (r, q) Distributed Electrons on the Formation of Solitary Wave Structure in Magnetized Negative Ion Plasma","authors":"N. Akhtar;S. Hussain","doi":"10.1109/TPS.2024.3472696","DOIUrl":"https://doi.org/10.1109/TPS.2024.3472696","url":null,"abstract":"Ion-acoustic solitary waves in the negative ion plasmas in the presence of generalized (r, q) distributed electrons are studied. Equations of states for positive and negative ions are included in magnetized plasma. Reductive perturbation method (RPM) are applied to derive the Zakharov-Kuznetsov (ZK) equation. The impact of variation of spectral indices on propagation characteristic of ion acoustic solitary waves in negative ion plasma is discussed. The effect of negative ion temperature in the presence of generalized distribution of electrons is also presented. Our findings predict that equation of state of negative ions affects amplitude and width of the nonlinear solitary structure significantly. Our findings are applicable to laboratory as well as space plasmas where negative ion plasmas exist with magnetic field, and a flat-top feature for low-energy electrons and a high-energy tail in the distribution function of the electrons have been observed.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 8","pages":"3094-3102"},"PeriodicalIF":1.3,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142600342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-24DOI: 10.1109/TPS.2024.3476451
Yadong Zhang;Ao Zhou;Xiong Lin;Zhiqiang Sun
Improving efficiency is a major area of research in the field of coil launchers. Two types of coil launchers are the reluctance coil launcher and the induction coil launcher. Reluctance coil launchers use a ferromagnetic armature, which is generally smaller in diameter due to the armature’s magnetic saturation and higher density, while induction coil launchers use a conductive armature, which is generally larger in diameter. To improve the efficiency of coil launchers, this article proposes a hybrid armature structure for coil launchers in which the front end of the ferromagnetic armature is placed at the end of the coil and connected to the conductive armature by an insulating material half the length of the coil. To compare the efficiency of the hybrid armature with that of the original armature, three coil launchers of 11.8, 18.4, and 50 mm bore were selected to simulate the hybrid armature with different parameters and to verify the consistency of the simulation and experiment of the hybrid armature. The final results show that the efficiency of the ferromagnetic armature is better than that of the hybrid armature at 11.8 mm aperture. At 18.4 mm, the hybrid armature efficiency is 9.12%, an improvement of 4.08% compared to the original ferromagnetic armature. At 50 mm bore, at 1000 V, the optimum efficiency of the hybrid armature is 3.17%, an improvement of 2.73% compared to an aluminum armature of the same mass with load, at 2000 V, the optimum efficiency of the hybrid armature is 7.87%, an improvement of 5% compared to an aluminum armature of the same mass with load, and at 3000 V, the efficiency of the hybrid armature is lower than that of the aluminum armature directly with load. The findings provide new and effective ideas for improving the efficiency of coil launchers.
提高效率是线圈发射器领域的一个主要研究领域。线圈发射器分为磁阻线圈发射器和感应线圈发射器两种。磁阻线圈发射器使用铁磁衔铁，由于衔铁的磁饱和度和密度较高，其直径一般较小；而感应线圈发射器使用导电衔铁，其直径一般较大。为了提高线圈发射器的效率，本文提出了一种用于线圈发射器的混合衔铁结构，其中铁磁衔铁的前端置于线圈的末端，并通过长度为线圈一半的绝缘材料与导电衔铁相连。为了比较混合电枢与原始电枢的效率，选择了孔径分别为 11.8 毫米、18.4 毫米和 50 毫米的三个线圈发射器来模拟不同参数下的混合电枢，并验证混合电枢模拟与实验的一致性。最终结果表明，在孔径为 11.8 毫米时，铁磁电枢的效率优于混合电枢。在 18.4 毫米孔径时，混合电枢的效率为 9.12%，比原来的铁磁电枢提高了 4.08%。在孔径为 50 毫米、电压为 1000 V 时，混合电枢的最佳效率为 3.17%，与带负载的同质量铝电枢相比提高了 2.73%；在电压为 2000 V 时，混合电枢的最佳效率为 7.87%，与带负载的同质量铝电枢相比提高了 5%；在电压为 3000 V 时，混合电枢的效率低于直接带负载的铝电枢。这些发现为提高线圈发射器的效率提供了新的有效思路。
{"title":"Efficiency Study of Hybrid Armatures With Coil Launchers of Different Calibres","authors":"Yadong Zhang;Ao Zhou;Xiong Lin;Zhiqiang Sun","doi":"10.1109/TPS.2024.3476451","DOIUrl":"https://doi.org/10.1109/TPS.2024.3476451","url":null,"abstract":"Improving efficiency is a major area of research in the field of coil launchers. Two types of coil launchers are the reluctance coil launcher and the induction coil launcher. Reluctance coil launchers use a ferromagnetic armature, which is generally smaller in diameter due to the armature’s magnetic saturation and higher density, while induction coil launchers use a conductive armature, which is generally larger in diameter. To improve the efficiency of coil launchers, this article proposes a hybrid armature structure for coil launchers in which the front end of the ferromagnetic armature is placed at the end of the coil and connected to the conductive armature by an insulating material half the length of the coil. To compare the efficiency of the hybrid armature with that of the original armature, three coil launchers of 11.8, 18.4, and 50 mm bore were selected to simulate the hybrid armature with different parameters and to verify the consistency of the simulation and experiment of the hybrid armature. The final results show that the efficiency of the ferromagnetic armature is better than that of the hybrid armature at 11.8 mm aperture. At 18.4 mm, the hybrid armature efficiency is 9.12%, an improvement of 4.08% compared to the original ferromagnetic armature. At 50 mm bore, at 1000 V, the optimum efficiency of the hybrid armature is 3.17%, an improvement of 2.73% compared to an aluminum armature of the same mass with load, at 2000 V, the optimum efficiency of the hybrid armature is 7.87%, an improvement of 5% compared to an aluminum armature of the same mass with load, and at 3000 V, the efficiency of the hybrid armature is lower than that of the aluminum armature directly with load. The findings provide new and effective ideas for improving the efficiency of coil launchers.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 8","pages":"3352-3359"},"PeriodicalIF":1.3,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142600226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vacuum circuit breakers are widely used in medium-voltage power systems, and the post-arc breakdown is a key factor limiting performance of the vacuum circuit breakers. In this work, a 2-D particle-in-cell/Monte Carlo collisional model is developed to investigate the post-arc breakdown. The residual plasma, metal vapor, inhomogeneous temperature distribution and electron emission on the post-arc cathode surface and various collisions between charged particles, and metal vapor are taken into consideration in the model. Simulation results show that the post-arc breakdown initiates in the vicinity of the post-arc cathode center. At the moment when the post-arc breakdown occurs, a potential hump forms near the post-arc cathode center, and the plasma density increases by two orders, which are consistent with the published result obtained by 1-D hybrid simulation model. Simulation results on the effect of metal vapor density show that the post-arc breakdown occurs earlier with increasing metal vapor density, and the post-arc breakdown cannot occur when the metal vapor density is below 1020 m−3.
{"title":"Two-Dimensional Particle-in-Cell/Monte Carlo Collisional Simulation of the Post-Arc Breakdown in Vacuum Circuit Breakers","authors":"Lijun Wang;Zhuo Chen;Dan Wang;Zhuoxi Lian;Zhiwei Wang;Runming Zhang","doi":"10.1109/TPS.2024.3449271","DOIUrl":"https://doi.org/10.1109/TPS.2024.3449271","url":null,"abstract":"Vacuum circuit breakers are widely used in medium-voltage power systems, and the post-arc breakdown is a key factor limiting performance of the vacuum circuit breakers. In this work, a 2-D particle-in-cell/Monte Carlo collisional model is developed to investigate the post-arc breakdown. The residual plasma, metal vapor, inhomogeneous temperature distribution and electron emission on the post-arc cathode surface and various collisions between charged particles, and metal vapor are taken into consideration in the model. Simulation results show that the post-arc breakdown initiates in the vicinity of the post-arc cathode center. At the moment when the post-arc breakdown occurs, a potential hump forms near the post-arc cathode center, and the plasma density increases by two orders, which are consistent with the published result obtained by 1-D hybrid simulation model. Simulation results on the effect of metal vapor density show that the post-arc breakdown occurs earlier with increasing metal vapor density, and the post-arc breakdown cannot occur when the metal vapor density is below 1020 m−3.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 8","pages":"3228-3236"},"PeriodicalIF":1.3,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142600191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-24DOI: 10.1109/TPS.2024.3434383
Quanxin Li;Guohua Yang;Jinliang He
The azimuthal magnetic fields of lightning M-components at various distance ranges were presented in this article. Two guided-wave models, namely, the classical guided-wave M-component model and the modified guided-wave M-component model, incorporating exponential current decay along the channel, were considered. Both fast and slow M-component current waveforms were utilized in the analysis. The study examined the magnetic field differences between the two models at close, intermediate, and far distance ranges. It was found that the discrepancies between the magnetic fields predicted by the classical guided-wave M-component model (CGM) and modified guided-wave M-component model (MGM) were relatively small at close distances. However, these differences became more noticeable at intermediate and far distances. It was observed that the amplitude differences were more prominent for the fast M-component compared with that of the slow M-component. The study also included a sensitivity analysis on the radiated magnetic fields, which likely explored the factors influencing the magnitude of the lightning M-component magnetic fields.
本文介绍了不同距离范围内闪电 M 分量的方位磁场。文章考虑了两种导波模型，即经典的导波 M 分量模型和修正的导波 M 分量模型，后者包含了沿通道的指数电流衰减。分析中使用了快速和慢速 M 分量电流波形。研究考察了两种模型在近、中、远距离范围内的磁场差异。研究发现，经典导波 M 分量模型（CGM）和修正导波 M 分量模型（MGM）预测的磁场在近距离时差异相对较小。然而，在中距离和远距离时，这些差异变得更加明显。据观察，与慢速 M 分量相比，快速 M 分量的振幅差异更为明显。研究还包括对辐射磁场的敏感性分析，这可能是为了探索影响闪电 M 分量磁场大小的因素。
{"title":"On the Comparison of Lightning M-Component Classical and Modified Guided-Wave Models From the Aspects of Azimuthal Magnetic Fields","authors":"Quanxin Li;Guohua Yang;Jinliang He","doi":"10.1109/TPS.2024.3434383","DOIUrl":"https://doi.org/10.1109/TPS.2024.3434383","url":null,"abstract":"The azimuthal magnetic fields of lightning M-components at various distance ranges were presented in this article. Two guided-wave models, namely, the classical guided-wave M-component model and the modified guided-wave M-component model, incorporating exponential current decay along the channel, were considered. Both fast and slow M-component current waveforms were utilized in the analysis. The study examined the magnetic field differences between the two models at close, intermediate, and far distance ranges. It was found that the discrepancies between the magnetic fields predicted by the classical guided-wave M-component model (CGM) and modified guided-wave M-component model (MGM) were relatively small at close distances. However, these differences became more noticeable at intermediate and far distances. It was observed that the amplitude differences were more prominent for the fast M-component compared with that of the slow M-component. The study also included a sensitivity analysis on the radiated magnetic fields, which likely explored the factors influencing the magnitude of the lightning M-component magnetic fields.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 8","pages":"3185-3192"},"PeriodicalIF":1.3,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142600264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-24DOI: 10.1109/TPS.2024.3417518
Bofeng Zhu;Guanxiang Zhang;Xiao Zhang;Yun Guo;Junyong Lu
This article proposes and studies a new type of air-core compulsator (compensated pulse alternator) for electromagnetic railgun, which realizes the brushless rotating-field electric excitation based on an axially cascaded exciter. The characteristics of the nonrectifier and inverse connection sequence of rotor full pitch winding make it different from the previous cascaded synchronous generator or doubly fed generator. Therefore, it can not only ensure a brushless and slip-ring-free structure, but also the advantages of high rotational reliability and excitation efficiency. The operation principle and design method are given first, and then the key application performance indexes such as self-excitation process, output power, energy storage density, and energy conversion efficiency of a scaled prototype are analyzed in detail. The study results show that the output power density of the scaled prototype can reach 629 MW/m3, and pulse energy storage density can reach more than 1.58 MJ/m3, which verifies the feasibility of the novel compulsator in principle and implementation, as well as advantages over the traditional hybrid energy storage scheme (battery and capacitor) in volume and weight. The relevant conclusions have positive reference significance for the lightweight and miniaturization of pulse power supply (PPS) for electromagnetic energy equipment.
{"title":"Study on the Principle and Performance of a Novel Synchronous Cascaded Air-Core Brushless Compulsator","authors":"Bofeng Zhu;Guanxiang Zhang;Xiao Zhang;Yun Guo;Junyong Lu","doi":"10.1109/TPS.2024.3417518","DOIUrl":"https://doi.org/10.1109/TPS.2024.3417518","url":null,"abstract":"This article proposes and studies a new type of air-core compulsator (compensated pulse alternator) for electromagnetic railgun, which realizes the brushless rotating-field electric excitation based on an axially cascaded exciter. The characteristics of the nonrectifier and inverse connection sequence of rotor full pitch winding make it different from the previous cascaded synchronous generator or doubly fed generator. Therefore, it can not only ensure a brushless and slip-ring-free structure, but also the advantages of high rotational reliability and excitation efficiency. The operation principle and design method are given first, and then the key application performance indexes such as self-excitation process, output power, energy storage density, and energy conversion efficiency of a scaled prototype are analyzed in detail. The study results show that the output power density of the scaled prototype can reach 629 MW/m3, and pulse energy storage density can reach more than 1.58 MJ/m3, which verifies the feasibility of the novel compulsator in principle and implementation, as well as advantages over the traditional hybrid energy storage scheme (battery and capacitor) in volume and weight. The relevant conclusions have positive reference significance for the lightweight and miniaturization of pulse power supply (PPS) for electromagnetic energy equipment.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 8","pages":"3310-3319"},"PeriodicalIF":1.3,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142600282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Major disruption poses a significant challenge to the safe operation of tokamaks, so disruption mitigation is a key problem to be solved in tokamak. Currently, the fundamental strategy of disruption mitigation involves actively injecting significant quantities of impurity gas or solids (such as neon, argon, deuterium, etc.) to generate sufficient radiation power for dissipating the plasma’s energy. The most commonly used disruption mitigation devices now are massive gas injection (MGI) and shattered pellet injection (SPI). However, The impurity injection rate is low, resulting in shallow deposits in the tokamak. Electromagnetic pellet injection (EMPI) is a relatively new generation of disruption mitigation system developed in J-TEXT Tokamak. The system is based on the electromagnetic rail run concept. It uses electromagnetic force to launch the armature with an impurity pellet. The EMPI has been tested several times and the speed of the pellet has broken through the speed of sound, far exceeding the launch speed of the traditional disruption mitigation system. This means impurity is deposited at a deeper location. However, the rail length of EMPI is too long and the rail ablation is serious, so it is a challenging problem to satisfy the tokamak installation space requirements. Therefore, based on the EMPI, an enhanced EMPI is designed, which increases the electromagnetic force by increasing the magnetic field intensity within the bore. This enables the rail length to be decreased to meet the specified condition. Building upon this foundation, various armature-rail coupling structures have been designed. These structures are subjected to COMSOL finite element simulation to determine which rail-armature interface exhibits minimal ablation, superior electrical contact, and maximal armature launch velocity. Subsequently, the optimal rail-armature coupling scheme is validated through an experimentation test.
{"title":"Optimization of Rail-Armature Coupling for the Enhanced Electromagnetic Pellet Injection in J-TEXT Tokamak","authors":"Zisen Nie;Zhongyong Chen;Wei Yan;Shengguo Xia;Yinlong Yu;Guinan Zou;Fanxi Liu;Yu Zhong;Jiangang Fang;Xun Zhou;Yuwei Sun;Yuan Sheng;You Li","doi":"10.1109/TPS.2024.3473029","DOIUrl":"https://doi.org/10.1109/TPS.2024.3473029","url":null,"abstract":"Major disruption poses a significant challenge to the safe operation of tokamaks, so disruption mitigation is a key problem to be solved in tokamak. Currently, the fundamental strategy of disruption mitigation involves actively injecting significant quantities of impurity gas or solids (such as neon, argon, deuterium, etc.) to generate sufficient radiation power for dissipating the plasma’s energy. The most commonly used disruption mitigation devices now are massive gas injection (MGI) and shattered pellet injection (SPI). However, The impurity injection rate is low, resulting in shallow deposits in the tokamak. Electromagnetic pellet injection (EMPI) is a relatively new generation of disruption mitigation system developed in J-TEXT Tokamak. The system is based on the electromagnetic rail run concept. It uses electromagnetic force to launch the armature with an impurity pellet. The EMPI has been tested several times and the speed of the pellet has broken through the speed of sound, far exceeding the launch speed of the traditional disruption mitigation system. This means impurity is deposited at a deeper location. However, the rail length of EMPI is too long and the rail ablation is serious, so it is a challenging problem to satisfy the tokamak installation space requirements. Therefore, based on the EMPI, an enhanced EMPI is designed, which increases the electromagnetic force by increasing the magnetic field intensity within the bore. This enables the rail length to be decreased to meet the specified condition. Building upon this foundation, various armature-rail coupling structures have been designed. These structures are subjected to COMSOL finite element simulation to determine which rail-armature interface exhibits minimal ablation, superior electrical contact, and maximal armature launch velocity. Subsequently, the optimal rail-armature coupling scheme is validated through an experimentation test.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 8","pages":"3326-3334"},"PeriodicalIF":1.3,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142600279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Electromagnetic-driven projectile spin launching technology is an important way to achieve high-precision firing in the railgun, but there is still a lack of sufficient research on the structural design of the tail-connected revolving armature and experimental verification of the spin launching performance. In this article, first, a structural design scheme of a revolving armature with a tail-end connection is established and compared with the conventional armature structural design scheme. Second, the finite element calculation model of interference assembly is adopted, and the influence law of the improved armature structure parameters on the initial mechanical performance is obtained. The theoretical calculation results show that the change of armature structural parameters has a great influence on the contact area and little influence on the maximum equivalent stress. The contact force decreases sharply with the increase of the interference position L2, throat radius r, and crack width $c_w$ of the tail, and increases sharply with the increase of the tail thickness t and interference amount $Delta $ . Finally, the electromagnetic launching experiments with different launching energies are carried out on test projectiles with conventional armature and tail-connected armature. The experimental results show that the revolving armature with a tail-end connection can effectively improve the rotation speed, but it will also have some negative effects on the muzzle velocity and the contact state between the armature and the rail in the bore.
电磁驱动弹丸自旋发射技术是轨道炮实现高精度发射的重要途径，但目前在尾端连接旋转衔铁的结构设计和自旋发射性能的实验验证方面仍缺乏足够的研究。本文首先建立了尾端连接旋转电枢的结构设计方案，并与传统电枢结构设计方案进行了比较。其次，采用过盈装配的有限元计算模型，得出改进后的衔铁结构参数对初始机械性能的影响规律。理论计算结果表明，电枢结构参数的改变对接触面积影响较大，而对最大等效应力影响较小。接触力随尾部过盈位置 L2、喉管半径 r 和裂纹宽度 $c_w$ 的增大而急剧减小，随尾部厚度 t 和过盈量 $Delta $ 的增大而急剧增大。最后，对传统衔铁和尾部连接衔铁的试验弹进行了不同发射能量的电磁发射实验。实验结果表明，尾端连接的旋转衔铁能有效提高旋转速度，但也会对枪口速度和衔铁与枪膛内导轨的接触状态产生一些负面影响。
{"title":"Structural Design of Revolving Armature With Tail End Connection and Its Electromagnetic Launching Performance Verification","authors":"Yong Liu;Tao Zhang;Kai Huang;Yanhui Chen;Wanying Wang;Wei Fan;Wei Guo","doi":"10.1109/TPS.2024.3475750","DOIUrl":"https://doi.org/10.1109/TPS.2024.3475750","url":null,"abstract":"Electromagnetic-driven projectile spin launching technology is an important way to achieve high-precision firing in the railgun, but there is still a lack of sufficient research on the structural design of the tail-connected revolving armature and experimental verification of the spin launching performance. In this article, first, a structural design scheme of a revolving armature with a tail-end connection is established and compared with the conventional armature structural design scheme. Second, the finite element calculation model of interference assembly is adopted, and the influence law of the improved armature structure parameters on the initial mechanical performance is obtained. The theoretical calculation results show that the change of armature structural parameters has a great influence on the contact area and little influence on the maximum equivalent stress. The contact force decreases sharply with the increase of the interference position L2, throat radius r, and crack width \u0000<inline-formula> <tex-math>$c_w$ </tex-math></inline-formula>\u0000 of the tail, and increases sharply with the increase of the tail thickness t and interference amount \u0000<inline-formula> <tex-math>$Delta $ </tex-math></inline-formula>\u0000. Finally, the electromagnetic launching experiments with different launching energies are carried out on test projectiles with conventional armature and tail-connected armature. The experimental results show that the revolving armature with a tail-end connection can effectively improve the rotation speed, but it will also have some negative effects on the muzzle velocity and the contact state between the armature and the rail in the bore.","PeriodicalId":450,"journal":{"name":"IEEE Transactions on Plasma Science","volume":"52 8","pages":"3335-3342"},"PeriodicalIF":1.3,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142600227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-23DOI: 10.1109/TNANO.2024.3485758
Leila Shakiba;Mohammad Reza Salehi;Farzin Emami
In this article, the graphene-based metamaterial perfect absorber was investigated in the terahertz region. Due to the geometrical symmetry of the proposed absorber structure, it is insensitive to changes in polarization and its angle, and the absorption value is almost the same over angles from 0 to 90 degrees. According to the configuration of the proposed structure, it is sensitive to changes in the refractive index. Placing graphene on top of the structure improves important sensing parameters, including sensitivity, due to good interaction with the analyte. The proposed structure is being investigated for medical applications including the diagnosis of malaria infection, cancer cells, and hemoglobin identification. The obtained results show the values of sensitivity, figure of merit, and quality coefficient as 2.63(THz/RIU), 175.3(1/RIU), and 523.35, respectively. The accuracy and correctness of the simulation results are checked using the method of equivalent circuit model and transfer matrix method, and there is good agreement between the simulation results and the mentioned methods.
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