The design and structural analysis of a coilgun for low acceleration of heavy loads

Variants of the coilgun are considered for use in microgravity experimental research. Subscale point designs are described for a payload of 50 kg and muzzle velocity of 30 to 40 m/s. A multiphase linear induction coilgun (LIL) (one stage with six coils and constant pitch) and a 4-stage reconnection coilgun were designed and analyzed. The results show that the requirement of very low acceleration is difficult, because the acceleration fluctuation of both designs is large. But differences between them are revealed. The induced current in the armature of the reconnection gun distributes much more unevenly than in the LIL, and this will cause mechanical and thermal problems. The efficiency of energy transformation in the connection gun is better than LIL of this specific design. Mechanical structural analysis results of the reconnection coilgun are also presented. The results show the coils are structurally sound. The armature is a nonlinear problem of both material and geometry so the available code Super SAP is adopted. However, the armature requires structural reinforcement.