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.

Interior Spectroscopic Investigation of the Propellant Energy Modes in an Arcjet Nozzle

Abstract: : Internal emission spectroscopy measurements were performed in the nozzle expansion region of a 26 kW class ammonia arcjet. A series of three optical access ports (0.020-inch diameter) were equally spaced along the center line of the expansion nozzle. Atomic and ionic excitation temperatures of H and NII were determined through the use of Boltzmann plots. Electron density measurements were also taken based upon Stark broadening of the hydrogen beta Balmer transition. It is believed that a change in the mechanism governing the electron density occurred just downstream of the constrictor between the first two access ports lending evidence that arc attachment is occurring in this region. Although the trends for excitation temperatures and electron density were similar to those previously observed in 1 kW arcjets, the temperature values were found to be significantly less. In addition, vibrational and rotational temperatures of NH were measured and appeared to be frozen throughout the expansion nozzle.

Development of an arcjet nuclear electric propulsion system for a 1993 flight demonstration

Abstract: The design and performance of an arcjet NEP spacecraft, suitable for use in the Space Nuclear Power System (SNPS) Reference Mission, are outlined. Several arcjet technology levels were considered in this study, and the vehicle design was based on an 30 kW ammonia arcjet system operating at an Isp of 1000 s and an efficiency of 45 percent. The arcjet/gimbal system, PPU and propellant feed-system are described. A 100 kWe SNPS was assumed and the spacecraft mass was baselined at 5500 kg excluding the propellant feed system. A radiation/arcjet efflux diagnostics package was included in the performance analysis. This spacecraft, launched from Kennedy, can perform a 50 degree inclination change and reach a final orbit of GEO with a 180 day trip time providing a six month active load for the SNPS. Advanced ammonia and hydrogen systems were examined for precursor SDI platform applications.

Optical measurements of plasma velocity and temperature in a low-rate, low-power LPPS system

Abstract: Low-pressure plasma spraying (LPPS) is a promising method of applying coatings to surfaces for thermal, chemical, and mechanical protection. The deposition of coatings with superior properties requires an improved understanding of this complex spray process, including the detailed understanding of the time–temperature and chemical history to which an injected particle is exposed during its travel through the high-temperature and high-velocity plasma jet. In this paper, we report on measurements of the temperatures and velocities within the plasma in a low-pressure argon–hydrogen arcjet spray plasma being developed for mesoscale manufacturing of mechanical components. The measurements reported here make use of laser absorption, laser-induced fluorescence, and optical emission spectroscopy of the H Balmer transition in atomic hydrogen. Both the absorption and a fluorescence methods take advantage of the well-known spectral line broadening of atomic hydrogen, to extract the arcjet temperature and electron density. Jet axial velocities are measured via the time of flight, as detected by optical emission, of convected disturbances caused by intrinsic fluctuations in the arc voltage. Measurements made for various anode (nozzle) geometries indicate that relatively low (; 1k m s mm) velocity gradients in the axial direction could be achieved with y1 y1

Low power arcjet propellant feed system

Abstract: A lower power arcjet propellant feed system for delivering propellant to a low power arcjet. The low power arcjet propellant feed system includes a liquid propellant storage chamber for storing a liquid propellant. A gas generator in communication with the liquid propellant storage chamber generates a gaseous propellant upon receipt of the liquid propellant from the liquid propellant storage chamber. A gas plenum in communication with the gas generator accumulates the gaseous propellant from the gas generator up to a desired pressure. Actively controllable valves actively control the flow of the liquid propellant into the gas generator and actively control the flow of the resultant gaseous propellant out of the gas generator and into the gas plenum up to the desired pressure. A substantially continuous and stable low flow rate of gaseous propellant is then delivered to the low power arcjet.

An experimental study of energy loss mechanisms and efficiency considerations in the low power dc arcjet

Abstract: The potential utility of the low power dc arcjet in auxiliary propulsion was investigated. It was indicated that improvements in the areas of stability, energy efficiency, reliability, and electrode erosion are necessary to obtain a useful device. A water-cooled arcjet simulator was tested to investigate both the energy loss mechanisms at the electrodes and the stability of different conventional arcjet configurations in the presence of a vortex flow field. It is shown that in certain configurations only 25 to 30% of the input energy is lost to the electrodes. It is also shown that vortex stabilization is not difficult to obtain in many cases at the flow rates used and that a careful starting procedure is effective in minimizing electrode damage.