固体电枢非稳态电磁场和温度场的数值计算

Numerical Computation of Unsteady Electromagnetic and Temperature Fields in Solid Armature

根据麦克斯韦方程和热传导方程,建立电磁导轨炮固体电枢二维非稳态计算模型。运用有限差分P-R算法进行耦合求解,定量分析铜、铝块状、U形电枢内部磁感强度和温度分布。数值计算结果表明,在相同时刻,U形电枢比块状电枢的整体温升低,由于U形电枢的外形特点,在转角位置有局部高温出现;同时由于铜铝材料物理性质的差别,铜电枢比铝电枢发生熔融烧蚀的时间推迟。这说明与导轨具有良好接触的U形铜电枢是较好的选择。数值计算结果为固体电枢的结构设计和材料选择提供理论依据。

According to Maxwell and heat transfer equations, the 2D unsteady computational models of e- lectromagnetic railgun solid armature was built up. By use of P-R finite difference method, coupling cal- culations were performed to quantitatively analyze magnetic induction strength and temperature distribution in block copper, block aluminium, U-shaped copper or aluminium armatures. Numerical computation results showed that U-shaped armature has lower temperature rise value on the whole compared with the block armature at the same time. Because of the structural characteristics of the U-shape armature, there existed significant local high temperature at sharp corners. Due to the differences of physical properties between copper and aluminium, copper armature had retardative time in the range of fusing and ablation compared with the aluminum armature, h can be arrived at the conclusion that the U-shaped copper armature with good contact capability with rails is the better choice in solid armature design. Numerical computation results can provide theory basis for structure design and material selection of solid armature.