Thermo-structural modelling of a plasma discharge tube for electric propulsion. (5th April 2016)

• Record Type: Journal Article
• Authors: de Faoite, D.; Browne, D.J.; Del Valle Gamboa, J.I.; Stanton, K.T.
• Is Part Of: Applied thermal engineering. Volume 98(2016:Apr.)
• Page Start: 541
• Page End: 552
• Publication Date: 2016-04-05
• Subjects: Thermo-structural modelling -- Plasma -- Discharge tube -- Electric propulsion; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2015.12.054
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: Thermo-structural analyses were performed for an electric propulsion space thruster. Thermal stresses arise primarily from mismatches in thermal expansion coefficients. Aluminium nitride is a suitable material for a plasma containment tube. A design is presented allowing a thruster to operate at a power of at least 250 kW. Abstract: Potential thermal management strategies for the plasma generation section of a VASIMR ® high-power electric propulsion space thruster are assessed. The plasma is generated in a discharge tube using helicon waves. The plasma generation process causes a significant thermal load on the plasma discharge tube and on neighbouring components, caused by cross-field particle diffusion and UV radiation. Four potential cooling system design strategies are assessed to deal with this thermal load. Four polycrystalline ceramics are evaluated for use as the plasma discharge tube material: alumina, aluminium nitride, beryllia, and silicon nitride. A finite element analysis (FEA) method was used to model the steady-state temperature and stress fields resulting from the plasma heat flux. Of the four materials assessed, aluminium nitride would result in the lowest plasma discharge tube temperatures and stresses. It was found that a design consisting of a monolithic ceramic plasma containment tube fabricated from aluminium nitride would be capable of operating up to a power level of at least 250 kW.