Arcjet rocket

About: Arcjet rocket is a research topic. Over the lifetime, 1121 publications have been published within this topic receiving 9687 citations. The topic is also known as: Arcjet.

Radiative emission analysis of an expanding hydrogen arc plasma—II. Plume region diagnostics through radial emission

Abstract: A numerical and experimental investigation of the axial emission of 1 and 5 kW radiatively-cooled hydrogen arcjet thrusters is presented. The numerical study consists of an integration of the 1-D radiative transfer equation along the arcjet centerline to predict the axial emission spectral intensity. The complete visible spectrum is modeled, taking into account graybody thermal emission from the cathode and plasma radiation from hydrogen atoms and free electrons. A collisional-radiative model is used to determine the atomic hydrogen line emission. The modeling results suggest the feasibility of determining the cathode temperature and the arc region electron number density from the measured axial emission spectrum. Experimental measurements of the axial emission spectra were performed at several operating conditions. The cathode temperature is found to be in the neighborhood of the tungsten cathode melting point and increases with arcjet power at a constant mass flow rate, suggesting an increase in the current density at the arc attachment point. The measured arc region electron number density is also found to increase with power, confirming an increasing arc current density with arcjet power. Relatively flat radial profiles of electron number density measured in the arc indicate the importance of diffusional transport processes.

Velocity measurements in the plume of an arcjet engine

Abstract: A nonintrusive technique has been used to conduct a radial survey in the flow field of an arcjet engine plume. The technique measures the Doppler shift of an optically thin line resulting from recombination and relaxation processes in the high Mach number stream, in order to determine flow velocities. Atom temperature can also be calculated from the same Doppler-broadened line widths, when these shifts are measured with a scanning Fabry-Perot spectrometer whose design is presented in detail. 19 references.