Simulation and design of a hydrogen arcjet thruster seeded with cesium

In conventional arcjets the largest loss in efficiency is the energy required to ionize the propellant. Adding a small amount of a readily ionizable material should provide adequate electrical conductivity, without the main propellant being ionized, thereby reducing this frozen loss. To study the effects of seeding a hydrogen arcjet with cesium, a two-dimensional numerical model was developed. The ions and atoms are treated as one fluid and the electrons as a second. The flow was modelled by Navier-Stokes equations modified to account for thermal and chemical non-equilibrium. The equations were numerically integrated by MacCormacks predictor-corrector scheme and a TVD scheme. The electric potential was solved by successive over-relaxation. Results show that the seeded arcjet can be run with the cesium fully ionized but the hydrogen having minimal dissociation or ionization. When the flow passes through the high current density region of the anode arc attachment, the hydrogen was found to not ionize as previously feared even when run at comparatively high currents. The cesium is fairly uniformly spread throughout the constrictor, as is the current density, so there is no formation of a narrow arc as in conventional thrusters.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Aeronautics and Astronautics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2001

Author dc:creator

• Robertson, Darrel Kim, 1974-

Advisor dc:contributor.advisor

• Manuel Martinez-Sanchez.

• Aeronautics and Astronautics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/8702

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/8702