Simulation of helical coil electromagnetic launcher's radial force and design of armature

The radial magnetic field distribution of the helical coil electromagnetic launcher's driving coil is investigated by numerical simulation,from which a "D" shaped cross section armature is proposed and its best location is determined.The results show that,with the same size,the acceleration of the "D" shaped armature is bigger than the rectangular armature,i.e.,with the same length of the launcher,the muzzle velocity of the "D" shaped armature is bigger than the rectangular armature.Taking the "D" shaped armature as an example,the axial and radial force distribution of the armature coil and the driving coil is investigated.The results show that the radial forces on the armature coil and the driving coil are mainly swelling forces,and the structure surround the coils should be reinforced in the launcher design.