There are given the results of experimental and theoretical investigations of armature accelerator of railgun type with the metallic anchor. There are presented data of the experimental studies of process of metallic contacts erosion with the analysis of transition from the metallic contact to hybrid one and, further, to plasma contact. Three - dimensional mathematical simulation has confirmed the existence of reliable metallic contact before melting of armature material and transition to the arc mode of current flow after the boiling. There was received good correspondence of numerical and natural data.

Mathematical modelling in actual problems of science and technics