A practical electromagnetic launcher concept-part I: Primary structure design and armature optimal simulation

The electromagnetic rail launcher can accelerate a microscopic object to more than 2km/s. The general characteristics and research situation of simple railgun was analyzed. One of the main problems is the melting, discharge, erosion, and gouging, which reason is the current assembling in some special places. There are three kinds of factors contributing to the current assembling: short path priority in conductor because of electric potential distribution, skin effect because of pulse electric current, and velocity skin effect within the contact surface because of relatively sliding hypervelocity. On the other hand, as a practical military weapon, electromagnetic launcher must have the following features: large bore, high pressure, reliable, and efficient. A practical EM launcher concept was proposed in this paper. The concept had a main idea of splitting a bulky copper into strips to overcome the skin effect. Referring to topology, we also use the short path priority to reject the skin effect and the velocity skin effect. Besides, the structure strength of copper, the sliding wear of copper rail, and the parameters´ matching for optimal electromagnetic force were also considered. The primary optimal simulation on five kinds 1/6 armature was contrastively carried out; the optimal armature has a uniformed current distribution. Concretely, the uniformity coefficient on the armature´s head and the rails u_c= i_min / i_max ≈ 50%. The new concept may promote the EM launcher research work.