Observation of inertially-driven thermo-electro-dynamic mass lossfrom an electromagnetically accelerating armature

Abstract

The reasons for the heavy mass losses usually observed to occurfrom various parts of recovered solid armatures, even in cases where therewas no transition, remain unclear. We earlier suggested that the lossescould result from strong non-uniformities in the distribution ofthermodynamic, electrical and dynamic parameters in the body of theaccelerating armature, the so-called TED effects. As a consequence, somesurface areas of the armature can break away from the main body to beeither ejected forward or to lag behind by inertia. This paper presentsultra-high-speed camera sequences demonstrating continuous inertial massloss from the root of a C-shaped armature, where local currentconcentration gives rise to a strong heating of the material. The mass lossis particularly intensive when launched on the rails coated by an In-Gaeutectic. This may imply that the current concentration is stronger in therear part of the armature contact surfaces.