块状固体电枢非稳态电磁效应的三维数值模拟

Three-dimensional Numerical Simulation of Unsteady Electromagnetic Effect in Block Solid Armature

建立了电磁导轨炮块状电枢三维非稳态电磁扩散效应计算模型,运用有限差分法耦合计算了电磁场与温度场,得到了导轨及电枢内部磁感强度、电流密度和温度分布.数值计算结果表明,电枢运动会引起电流趋向表面流动并在电枢尾部与轨道接触面上趋于集中,使电枢尾部焦耳热剧增并导致高温烧蚀.与二维模型相比,三维模型能更加真实地反映电磁导轨炮发射过程中导轨和电枢中的物理现象,对理论和试验研究有指导作用.

A three-dimensional unsteady computational model about the electromagnetic effect in the block armature was built. Coupling calculation of temperature field and electromagnetic field were carried out hy using the finite difference method. The magnetic induction intensity, current density and temperature distributions were obtained. The results show the concentration of current at the left-hand corner of the rail-armature interface, and extremely high temperature, erosion occur at the edges of armature due to the joule heating. Compared with the two-dimensional model, the three-dimensional one can reflect the physical phenomenon in the armature during the launch process efficiently, and it offers reference for the theoretical and experimental research of the railgun.