Abstract
A non-segmented constricted arcjet is widely used as a compact high enthalpy wind tunnel and electric propulsion device. When argon is used as the operating gas, it operates in the low voltage mode, which is known to be unstable. The upstream subsonic flow conditions and the electrode configuration can influence its discharge instability and characteristics, but there is little research investigating them. The present study investigated these influences using computational fluid dynamics. The upstream rectification effect was found to be insignificant for the discharge characteristics. In contrast, the electrode configuration was shown to have a strong influence on the discharge mode: as the anode start position—the boundary between anode and insulator—moves downstream, the arc attachment point moves with it. This suggests that by adjusting the anode start position it is possible to shift the discharge voltage mode from low (5 V) to high (24 V).