Primary Structural Design and Optimal Armature Simulation for a Practical Electromagnetic Launcher

An electromagnetic (EM) rail launcher can accelerate a macroscopic object to >2 km/s. One of the main problems of a simple railgun is the ohmic heating to melt in some special places, which is caused by the current clustering property. The design theory and technologies for a practical EM launcher concept are analyzed. There are three kinds of factors contributing to the current clustering: 1) short path priority (SPP); 2) skin effect (SE); and 3) velocity SE (VSE). The method of splitting a bulky copper into multistrips can be used to overcome the current clustering. SPP can also be used to reject SE and VSE. Besides, the structure strength of copper, the sliding wear of copper rail, and the parameters' matching for optimal EM force are also considered. A practical EM launcher concept is proposed. After the primary structural design is accomplished, the optimal simulation on three kinds of 1/6 armature are carried out, and the results are compared. The optimal armature has a more uniformed current distribution among the three. As a quantitative result, the uniformity coefficient on the armature's head and the rails is ~ 50%. As a military weapon concept, the practical EM launcher has the following features: 1) large bore; 2) high pressure; 3) high reliability; and 4) high efficiency. The new concept work might promote the EM launcher research work.