Design and Test of a Single-Stage Double-Layer Multipole Field Electromagnetic Launcher With a Rotational Performance

A new type of multipole field electromagnetic launcher is designed in this paper, which has two parallel layers of multipole structure, and there is a 30-degree relative torsion angle between the inner and the outer one. The armature is designed as a complete and symmetrical hollow cylindrical metal sleeve with no slots. Owing to the superposition of the magnetic fields generated by the two layers, this novel structure can make the magnetic field density and eddy current distribution on the armature unbalanced, which generates an axial force and torque simultaneously. Simulations were conducted, and the magnetic field and the eddy current distribution were analyzed. The simulations indicate that this double-layer multipole field electromagnetic launcher achieves a rotational motion and a higher linear speed than that of single-layer structure. Experiments were performed and the results verified the correctness of the simulations. Due to its rotational performance, this configuration provides an approach to obtain gyroscopic stabilization for projectiles. It creates condition for multi-stage and combined mode applications because the armature does not need to be processed particularly to meet special requirements.