The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Bernardo Tellini - One of the best experts on this subject based on the ideXlab platform.
-
I2MTC - Measurement of rail current distribution in rail launchers
The Journal of Thoracic and Cardiovascular Surgery, 2014Co-Authors: Roberto Ferrero, Mirko Marracci, Bernardo TelliniAbstract:This paper deals with the measurement of current distribution across the rails of rail launchers. The proposed approach is based on inductive method by magnetically coupling an array of search loops with the rail-Armature circuit. The procedure was already successfully employed for current distribution measurements among the brushes of multi-brush Armatures and its extension to the current distribution reconstruction across the rails is here discussed. The method sensitivity and the measurement model uncertainty in a simple case study are firstly analyzed based on an analytical model formulation, to obtain information about the applicability of this approach. Then, a finite element analysis and experimental results are presented, discussing various rails-Armature configurations.
Roberto Ferrero - One of the best experts on this subject based on the ideXlab platform.
-
I2MTC - Measurement of rail current distribution in rail launchers
The Journal of Thoracic and Cardiovascular Surgery, 2014Co-Authors: Roberto Ferrero, Mirko Marracci, Bernardo TelliniAbstract:This paper deals with the measurement of current distribution across the rails of rail launchers. The proposed approach is based on inductive method by magnetically coupling an array of search loops with the rail-Armature circuit. The procedure was already successfully employed for current distribution measurements among the brushes of multi-brush Armatures and its extension to the current distribution reconstruction across the rails is here discussed. The method sensitivity and the measurement model uncertainty in a simple case study are firstly analyzed based on an analytical model formulation, to obtain information about the applicability of this approach. Then, a finite element analysis and experimental results are presented, discussing various rails-Armature configurations.
Lixue Chen - One of the best experts on this subject based on the ideXlab platform.
-
Influence of Caliber Height on Armature Current Melt Erosion in Rail Gun
IEEE Transactions on Plasma Science, 2020Co-Authors: Lixue Chen, Jinghui Ruan, Zengji Wang, Shengguo XiaAbstract:Keeping good electrical contact at the Armature/rail interface and the structural integrity of the Armature during electromagnetic launching is critical to its performance. In this article, the influence of Armature height on the erosion of Armature’s tail is studied through experiments. The results of the Armature current melt erosion (CME) of different linear current densities are summarized. For Armatures with lower height, the CME tends to develop vertically, which is not conducive to keeping the structural integrity of the Armature. For Armature with higher height, the CME develops from the middle position of the Armatures’ tails to both horizontal and vertical directions. In this article, the finite element software COMSOL is used to analyze the initial contact position of the Armature/rail and the current density distribution of the Armature/rail interface. The reasons for the starting position of Armature CME and the differences in the morphology of Armature CME in three different heights are explained. Finally, from the theoretical point of view, the influencing factors of Armature CME are analyzed.
-
Some Key Parameters of Monolithic C-Type Armature in Rectangular Caliber Railgun
IEEE Transactions on Plasma Science, 2017Co-Authors: Lixue Chen, Shengguo Xia, Zhao YuanAbstract:Monolithic C-type Armature is one of the most important Armatures in electromagnetic railgun. Some key parameters of monolithic C-type Armature in rectangular caliber railgun system—width of Armature X, height of Armature Y, thickness of Armature’s throat $d_{0}$ , length of Armature’s tail $d_{1}$ , thickness of trailing edge of Armature’s tail $d_{2}$ , and angle of Armature’s tail $\theta $ —are studied in this paper. By introducing current carrier margin coefficient named $\alpha $ , ratio of Armature thickness to Armature width named $\beta $ , ratio of Armature height to Armature width named $\gamma $ , and ratio of length of Armature’s tail to Armature height named $\kappa $ , equations of some key parameters of monolithic C-type Armature in rectangular caliber railgun system are proposed. Based on analysis of mass of Armature, electromagnetic contact force between Armature and rail, mechanical strength of Armature’s tail, and inductance gradient, relationship of some key parameters of monolithic C-type Armature in rectangular caliber railgun system are proposed. Conclusion can be drawn that increase of $\theta $ can reduce mass of Armature and improve mechanical strength of Armature’s tail, but electromagnetic contact pressure between Armature and rail will be decreased. Decrease of $\gamma $ could be a considerable way to remarkably increase inductance gradient, and then increase launch system efficiency.
-
Experimental study of Armature melt wear in solid Armature railgun
2014 17th International Symposium on Electromagnetic Launch Technology, 2014Co-Authors: Lixue Chen, Shengguo Xia, Zheng Xiao, Deng Feng, Liangliang TangAbstract:Transition is an important issue in rail electromagnetic launches which limits the performance of electromagnetic launch systems. In the launch progress, wear on contact surface of Armature significantly affects the morphology of contact surface and Armature structure. Studying wear, contact resistance and sliding friction coefficient of the contact surface is important to understand principles of transition and suppress transitions in electromagnetic launches. In this paper, special designed Armature, which makes the wear on Armature contact surface all melt wear, is used in rail launch experiments to measure the wear rate of melt wear and the effects of loading on wear. Launch experiment results show that the wear rate is represented by the average thickness of the aluminum debris left on the rail. The average wear rate is about 0.6 to 2 mm/m and the average debris thickness is in a range of 3–10 um in the experiments. Based on the idea of melt wear is the main part, the heat balance of Armature contact surface in launch process was analyzed. It is concluded that melt-wear absorbs mounts of heat generated on the surface, and the left heat goes into rails through the contact. The heat balance based equations was then derived, which established relationship among melt wear, launch parameters and material parameters. By the equations obtained, and using the data of launch experiments, the contact resistance of Armatures with 80 mm2 contact area is 2.5564 цй, the contact resistance of Armatures with 50 mm2 contact area is 4.0902 цй and the sliding friction coefficient is 0.1131.
-
study on the curve shape of c shaped Armature s trailing arms in rectangular bore railgun
IEEE Transactions on Plasma Science, 2013Co-Authors: Deng Feng, Lixue Chen, Shengguo Xia, Zheng Xiao, Ping YanAbstract:During the electromagnetic launch process, there is a contact surface between the trailing arm of C-shaped Armature and the rail. This contact is generally provided by the deformation of the trailing arm, from which it can keep a good metal–metal contact at the Armature-rail interface, while providing sufficient contact force to ensure the launch without transition. Nowadays, C-shaped Armatures with curved-surface trailing arms are used in rectangular bore railguns. In this paper, the effect of geometry change on the curve shape is investigated. Various kinds of reasonable curve shapes are explored and simulated by using finite element method. Contact pressure distributions and a series of contact characteristics variables of C-shaped Armature with different curve shapes are calculated and compared respectively. Eventually, the variation laws of contact characteristics at the Armature-rail interface with different kinds of curve shapes are acquired. 2-D and 3-D simulations are both carried out, and the simulation results are quite consistent with each other.
-
Studies on Interference Fit Between Armature and Rails in Railguns
IEEE Transactions on Plasma Science, 2011Co-Authors: Shengguo Xia, Lixue Chen, Zheng XiaoAbstract:There is an interference fit between the trailing arms of the monolithic C-shaped Armature and the rails to provide good solid-on-solid contact during the early portion of a railgun launch. In this paper, the contact interference between the rail and Armature in a railgun is calculated using a finite-element structural analysis code. The contact properties, including the contact pressure and contact area, are analyzed. It is found that a contact separation caused by the interference is inevitable in Armatures with line-shaped contact interference. The reduction of the contact interference in an Armature design cannot eliminate this kind of contact separation. A proper design of the Armature structure can decrease the length of the separation effectively. A new design of the contact interference is proposed. Both the experiments and calculations show that the new design of the contact interference can effectively improve the performance of the Armature.
Shengguo Xia - One of the best experts on this subject based on the ideXlab platform.
-
Influence of Caliber Height on Armature Current Melt Erosion in Rail Gun
IEEE Transactions on Plasma Science, 2020Co-Authors: Lixue Chen, Jinghui Ruan, Zengji Wang, Shengguo XiaAbstract:Keeping good electrical contact at the Armature/rail interface and the structural integrity of the Armature during electromagnetic launching is critical to its performance. In this article, the influence of Armature height on the erosion of Armature’s tail is studied through experiments. The results of the Armature current melt erosion (CME) of different linear current densities are summarized. For Armatures with lower height, the CME tends to develop vertically, which is not conducive to keeping the structural integrity of the Armature. For Armature with higher height, the CME develops from the middle position of the Armatures’ tails to both horizontal and vertical directions. In this article, the finite element software COMSOL is used to analyze the initial contact position of the Armature/rail and the current density distribution of the Armature/rail interface. The reasons for the starting position of Armature CME and the differences in the morphology of Armature CME in three different heights are explained. Finally, from the theoretical point of view, the influencing factors of Armature CME are analyzed.
-
Some Key Parameters of Monolithic C-Type Armature in Rectangular Caliber Railgun
IEEE Transactions on Plasma Science, 2017Co-Authors: Lixue Chen, Shengguo Xia, Zhao YuanAbstract:Monolithic C-type Armature is one of the most important Armatures in electromagnetic railgun. Some key parameters of monolithic C-type Armature in rectangular caliber railgun system—width of Armature X, height of Armature Y, thickness of Armature’s throat $d_{0}$ , length of Armature’s tail $d_{1}$ , thickness of trailing edge of Armature’s tail $d_{2}$ , and angle of Armature’s tail $\theta $ —are studied in this paper. By introducing current carrier margin coefficient named $\alpha $ , ratio of Armature thickness to Armature width named $\beta $ , ratio of Armature height to Armature width named $\gamma $ , and ratio of length of Armature’s tail to Armature height named $\kappa $ , equations of some key parameters of monolithic C-type Armature in rectangular caliber railgun system are proposed. Based on analysis of mass of Armature, electromagnetic contact force between Armature and rail, mechanical strength of Armature’s tail, and inductance gradient, relationship of some key parameters of monolithic C-type Armature in rectangular caliber railgun system are proposed. Conclusion can be drawn that increase of $\theta $ can reduce mass of Armature and improve mechanical strength of Armature’s tail, but electromagnetic contact pressure between Armature and rail will be decreased. Decrease of $\gamma $ could be a considerable way to remarkably increase inductance gradient, and then increase launch system efficiency.
-
Experimental study of Armature melt wear in solid Armature railgun
2014 17th International Symposium on Electromagnetic Launch Technology, 2014Co-Authors: Lixue Chen, Shengguo Xia, Zheng Xiao, Deng Feng, Liangliang TangAbstract:Transition is an important issue in rail electromagnetic launches which limits the performance of electromagnetic launch systems. In the launch progress, wear on contact surface of Armature significantly affects the morphology of contact surface and Armature structure. Studying wear, contact resistance and sliding friction coefficient of the contact surface is important to understand principles of transition and suppress transitions in electromagnetic launches. In this paper, special designed Armature, which makes the wear on Armature contact surface all melt wear, is used in rail launch experiments to measure the wear rate of melt wear and the effects of loading on wear. Launch experiment results show that the wear rate is represented by the average thickness of the aluminum debris left on the rail. The average wear rate is about 0.6 to 2 mm/m and the average debris thickness is in a range of 3–10 um in the experiments. Based on the idea of melt wear is the main part, the heat balance of Armature contact surface in launch process was analyzed. It is concluded that melt-wear absorbs mounts of heat generated on the surface, and the left heat goes into rails through the contact. The heat balance based equations was then derived, which established relationship among melt wear, launch parameters and material parameters. By the equations obtained, and using the data of launch experiments, the contact resistance of Armatures with 80 mm2 contact area is 2.5564 цй, the contact resistance of Armatures with 50 mm2 contact area is 4.0902 цй and the sliding friction coefficient is 0.1131.
-
study on the curve shape of c shaped Armature s trailing arms in rectangular bore railgun
IEEE Transactions on Plasma Science, 2013Co-Authors: Deng Feng, Lixue Chen, Shengguo Xia, Zheng Xiao, Ping YanAbstract:During the electromagnetic launch process, there is a contact surface between the trailing arm of C-shaped Armature and the rail. This contact is generally provided by the deformation of the trailing arm, from which it can keep a good metal–metal contact at the Armature-rail interface, while providing sufficient contact force to ensure the launch without transition. Nowadays, C-shaped Armatures with curved-surface trailing arms are used in rectangular bore railguns. In this paper, the effect of geometry change on the curve shape is investigated. Various kinds of reasonable curve shapes are explored and simulated by using finite element method. Contact pressure distributions and a series of contact characteristics variables of C-shaped Armature with different curve shapes are calculated and compared respectively. Eventually, the variation laws of contact characteristics at the Armature-rail interface with different kinds of curve shapes are acquired. 2-D and 3-D simulations are both carried out, and the simulation results are quite consistent with each other.
-
Studies on Interference Fit Between Armature and Rails in Railguns
IEEE Transactions on Plasma Science, 2011Co-Authors: Shengguo Xia, Lixue Chen, Zheng XiaoAbstract:There is an interference fit between the trailing arms of the monolithic C-shaped Armature and the rails to provide good solid-on-solid contact during the early portion of a railgun launch. In this paper, the contact interference between the rail and Armature in a railgun is calculated using a finite-element structural analysis code. The contact properties, including the contact pressure and contact area, are analyzed. It is found that a contact separation caused by the interference is inevitable in Armatures with line-shaped contact interference. The reduction of the contact interference in an Armature design cannot eliminate this kind of contact separation. A proper design of the Armature structure can decrease the length of the separation effectively. A new design of the contact interference is proposed. Both the experiments and calculations show that the new design of the contact interference can effectively improve the performance of the Armature.
Mirko Marracci - One of the best experts on this subject based on the ideXlab platform.
-
I2MTC - Measurement of rail current distribution in rail launchers
The Journal of Thoracic and Cardiovascular Surgery, 2014Co-Authors: Roberto Ferrero, Mirko Marracci, Bernardo TelliniAbstract:This paper deals with the measurement of current distribution across the rails of rail launchers. The proposed approach is based on inductive method by magnetically coupling an array of search loops with the rail-Armature circuit. The procedure was already successfully employed for current distribution measurements among the brushes of multi-brush Armatures and its extension to the current distribution reconstruction across the rails is here discussed. The method sensitivity and the measurement model uncertainty in a simple case study are firstly analyzed based on an analytical model formulation, to obtain information about the applicability of this approach. Then, a finite element analysis and experimental results are presented, discussing various rails-Armature configurations.