Numerical modeling of low-power argon arcjet thruster

In this paper, modeling study is performed to reveal the plasma flow and heat transfer characteristics of the low-power argon arcjet thruster. The all-speed SIMPLE algorithm is used for the solution of the governing equations. Computed results are presented concerning the temperature, velocity, Mach number and streamline distributions within the thruster nozzle and concerning the current density distributions on the anode-nozzle surface under typical operating conditions. It is found that the heating of the gaseous propellant takes place mainly in the cathode and constrictor regions and the highest plasma temperature appears at the location near the cathode tip where the current density assumes its maximum value. The plasma axial-velocity and temperature profiles along the nozzle axis increases rapidly at first and then decreases gradually as the plasma flows toward the thruster exit. The effects of different arc currents on the flow and heat transfer characteristics within the thruster nozzle are also investigated. Under typical operating conditions studied here, the computed specific impulses and mass flow rates of the argon arcjet thruster are roughly consistent with corresponding experimental data.