Arcjet thermal characteristics

The performance of water-cooled and radiation-cooled arcjet thrusters operating on both 1:2 nitrogen/hydrogen mixtures at 1-2 kW and on pure hydrogen at 1-4 kW are compared. To investigate the effects of test facility background pressure on performance, data were taken for both thrusters operating on hydrogen/nitrogen mixtures at facility background pressures nominally at 0.20 Pa and 20 Pa. It is shown that increasing the background pressure decreased the thruster performance, and simple pressure area corrections alone could not account for the observed degradation in performance.