OBSERVATION AND SIMULATION OF ARMATURE CONTACT PERFORMANCE IN THE CANNON-CALIBER ELECTROMAGNETIC GUN

Major components developed under the Cannon-Caliber Electromagnetic Gu n (CCEMG) Program are presently undergoing tests at the U.S. Army Rese arch Laboratory (ARL) located at Aberdeen Proving Ground (APG), MD. Th e CCEMG Launcher is a series-augmented barrel 2.25 m in length and has a rectangular bore cross section of 17.3 mm x 37.3 mm. The system is designed to operate with a peak current of 835 kA, a launch package ma ss of 185 g, and an exit velocity of 1,850 m/s. CCEMG is a multishot s ystem demonstrator. The test results we discuss here are for single-sh ot operation. The muzzle voltage in-an augmented launcher contains con tributions from the fields due to the augmenting turn. These imposed v oltage terms tend to mask the transition of the armature contact, ther eby making the transition event less discernable than In a simple rail gun. The Army Railgun Modular Simulator (ARMS) computer code has been modified to provide one-dimensional (1-D), lumped parameter model of t he launcher and contact wear at the armature-to-rail interface. The CC EMG launcher data are used to further validate the ARMS code and conta ct wear model. Additionally, a two-dimensional, transient finite diffe rence (2-D TFD) model is used to assess heating in the armature. In th is paper we present photographic and electrical data from two shots in which armature performance is simulated.