Synchronous induction coilgun (SICG) typically includes an array of drive coils and a conductive armature. The structure of the drive coil and armature can greatly affect the launching performance of SICG. The traditional drive coils and armatures have a cylinder-shaped structure for simplicity and ease of fabrication. In this article, a novel structural SICG with stepped drive coil and stepped armature (SA) is proposed and investigated. As a comparison, four structural SICGs are researched by static and transient simulations. The static simulation results show that the stepped drive coil makes the magnetic field larger and the center of the magnetic field moves backward toward the tail end. The transient simulation results indicate that the SA improves the eddy current distribution and the positive propulsion force and weakens the reverse electromagnetic force and the armature capture effect at the same time. As a result of integrating the above characteristics, the new structural SICG with stepped drive coil and SA makes the optimal trigger position of armature move backward by 7 mm and improves the muzzle velocity by 4.79% and the launch efficiency by 9.82%.

中文翻译：

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带阶梯线圈发射器和阶梯电枢的同步感应线圈炮的研究

同步感应线圈枪 (SICG) 通常包括驱动线圈阵列和导电电枢。驱动线圈和衔铁的结构可以极大地影响SICG的发射性能。传统的驱动线圈和电枢具有圆柱形结构，以简化和易于制造。在本文中，提出并研究了一种具有阶梯式驱动线圈和阶梯式电枢 (SA) 的新型结构 SICG。作为比较，通过静态和瞬态模拟研究了四种结构 SICG。静态仿真结果表明，阶梯式驱动线圈使磁场变大，磁场中心向尾端后移。瞬态仿真结果表明，SA改善了涡流分布和正向推进力，同时减弱了反向电磁力和电枢俘获效应。由于综合了上述特点，采用阶梯式驱动线圈和SA的新型结构SICG使衔铁的最佳触发位置后移7毫米，使初速提高4.79%，发射效率提高9.82%。