A Factorial Experiment to Characterize the Small-Caliber Launcher

The small-caliber launcher (SCL) is a 2-m-long railgun with a 1-in bore. The gun line houses 91.5-in (232.4 cm) rails with a 1.25 in 0.25 in thickness. A need was determined to characterize the gun line for maximum performance of exit velocity, peak velocity, and efficiency by using factorial experiments with linear regression modeling. In this paper, a factorial experiment was designed and conducted in order to study the effect of key design factors (i.e., charge voltage, armature mass, and starting location) on the performance of the SCL. This statistical method enables the efficient and accurate characterization of the joint effects of these design factors on the SCL. Analysis of variance indicates that a combination of low armature mass (i.e., 49 g), high charge voltage (i.e., 12 kV), and short starting location (i.e., 29.6 cm) maximizes the SCL´s exit velocity, peak velocity, and efficiency. Furthermore, some interactions between these factors were found to cause significant statistical effects on SCL performance.