Experimental and Numerical Studies of a Low-Power N2 Arcjet Thruster.

Abstract

This paper describes the experimental and numerical studies of a laboratory model of the low-power nitrogen arcjet thruster that was developed to provide thruster performance data to validate numerical results. The arcjet thruster was operated by using a nozzle 1.0mm in constrictor diameter. Thrust and input power were measured for various arc currents and nitrogen mass flow rates. The operation was done at power levels ranging from 156W to 540W and nitrogen mass flow rates from 5mg/s to 30mg/s. Typical specific impulse obtained in the experiment was 188s at 542W. Numerical simulation was conducted by using the physical model of a thermochemical nonequilibrium gaseous flow, a two-temperature model consisting of heavy particle and electron temperatures. The flowfield equations were numerically solved by combining with the Maxwell’s equation and the generalized Ohm’s law. It is shown that the predicted thruster performance is higher than the experimental data for the specific impulse, and the possible causes for this trend are discussed.