Electromagnetic launch technology for hypervelocity applications - the multiple armature approach of ISL

摘要

Among the various techniques of electromechanical energy conversion, the electromagnetic railgun has proved to be the most effective solution for achieving hypervelocity. Railguns are characterized by a simple functional principle but require sliding electrical contacts at conditions not to be found in any other technical application. Sliding contact in railguns is achieved using a sliding conductor, (termed "armature"). The armature is part of the launch package and experiences large dynamic and thermal loading during launch. Progress made at the French-German Research Institute of Saint-Louis (ISL) has led to the development of a solution to the sliding contact problem through the use of multiple-brush armatures. Multiple brushes, each containing thousands of metal fibres, are incorporated into a composite-fibre sabot that enables reliable multi-spot contact modes with the copper rails. This paper presents experimental results obtained using multi-spot contact technology. Namely, the realization of a high-power DES (Distributed Energy Storage) railgun PEGASUS (Project of an Electric Gun Arrangement to Study the Utilization of Systems) and the multi-shot project RAFIRA (Rapid Fire Railgun). In addition, a section of this paper is dedicated to impact physics phenomena related to the use of ISL's armature approach. Experimental results regarding the impact of composite sabots into steel targets are presented and the potential use of electromagnetic railguns as tools for future investigations into high-speed impact physics are discussed.