MODELING OF A DIRECT-CURRENT ARC IN A PLASMATRON WITH STEP ELECTRODES A. F. Bublievskii , O. I. Yas'ko , and E. I. Yurinok UDC 537.523.5 By methods of physical modeling using a linear ridge regression it is established that in direct-current plasmatrons with step electrodes the volt-ampere characteristic of the arc is formed by heat-transfer processes, while gasdynamic factors have a slight effect. Generalized VACs of unilateral- and bilateral-emission plasmatrons in blowing the arc with air and hydrogen are refined. JEPTER7492019995 JEPTER749205