Characteristic Studies Of C-shaped Solid Armatures In Electromagnetic Launch

Electromagnetic rail launch technology, which has a broad military application foreground, is one of the hottest top technologies at present, and its huge potential attracts the main military countries to study on both theory and application. Armature takes a important role in the whole electromagnetic launch process, so the studies on it are also important for the application and development of electromagnetic launch technology. From theoretic and experimental researches, we find out that the solid C-shaped armature has many superior characters, and it is a popular armature style in the studies of solid armature railgun in the world.In C-shaped armatures, high current density centralization in one part could lead to a high partial temperature, makes the rail and armature material melted down, eroded and fracted, and the armature structure has an important effect on the distribution of current density and temperature field. An important consideration in the design of solid armatures is whether the solid contact between the armature and rail could be kept well, this comes down to the contact pressure of the interface. As we know, contact pressure is not only related to the mechanism design, but also influenced by the armature structure. At the same time, the accelerating force on armature in the bore is related to both the characters of driving current and the armature structure. Therefore, studies on the effects of solid armature structure on the distribution of current field and temperature field inside the armature in the process of electromagnetic rail launch, are important for the solid armature railguns.In order to make the effects of various parameters in process of electromagnetic launch clear, on the assumption of the nondisjunction and ideal entire contact between the armature and rail, this paper analysed the inner current field distribution and the consequently temperature field distribution characters of C-shaped armature in the launching process based on ANSYS, furthermore, to understand the effect rules that the changes of the structure and material of C-shaped armature to the inner armature current field, temperature field, the condition of contact between armature and rail and the electromagnetic forces work in the launching process. Thereby, provides references for designing reasonable armature structure.The simulation result indicates that, suppose the armature is relative rest to the rail, when the resistivity of armature is bigger than the rail's, a current density concentration area was formed in the head of the armature, and a current density concentration area was formed at the tail of the armature while the rail's is bigger. At the same time, the resistivity also has effect on the skin depth of the current density. The max current density and joule heat of the armature decreased while the driving force on armature increased by the increase of the side thickness and front thickness, but the length of the armature had little effect on the max current density and joule hear value, and shows no disciplinary effect on driving force. The distribution of current density and joule heat could be improved by adding leading edge at the front of the armature, at the same time, the driving force on armature would be increased while the internal stress of armature decreased. The change of curvature radius of inboard surface has a great effect on the max values and distribution areas of current density and joule heat. The driving force increased and internal stress decreased along with the decrease of inboard surface's curvature radius.