Gas mixtures of hydrogen and nitrogen with the mole ratio(r) between 1.0~2.0 were used as the propellant,and operation parameters,such as arc current,arc voltage,inlet pressure,chamber pressure,gas flow rates and nozzle temperature,were measured in-situ.The dependence of the thrust,specific impulse and efficiency on the specific power,r and total mass flow rate of the propellant were analyzed.Results showed that the thrust increases appreciably at high mass flow rate together with high r.However,for the improvement of specific impulse and efficiency,high r plays a more important role.Especially,the specific impulse increases significantly with the increasing r.

Low power H_2-N_2 arcjet thruster operation and performance

To sustain the arc in the arcjet, the swirl is thought to be necessary. This paper conducts a numerical study on various geometry and input conditions. The effect of swirl and wall temperature of a nozzle on the plasma flow, arc behavior, and performance parameter of low power arcjet has been studied. The physics behind the working of low power arcjet and behavior of swirl velocity has been plotted. Various aspect of swirl, which stabilizes the arc, is also discussed.

Effect of Swirl and Wall Heat Transfer on the Performance of Arcjet Thrusters Using Numerical Modeling

The extension to a higher specific impulse of an arcjet requires deeper understanding of the physics process in the thruster. In this paper, low-power arcjet thrusters are studied numerically using argon as the propellant. The all-speed SIMPLE algorithm is used for the solution of the governing equations, including temperature- and pressure-dependent gas properties. Computed results are presented concerning the temperature, pressure, axial velocity and Mach number distributions within in the thruster nozzle under typical operating conditions. It is found that the heating of the propellant takes place mainly in the constrictor. 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. The effects of the geometrical sizes of the arcjet are also investigated.

Hai-Xing Wang

Papers

Two-Dimensional LTE Modeling of a Low-Power Argon Arcjet Thruster