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Plasma Chemistry and Plasma Processing

, Volume 11, Issue 4, pp 529–543 | Cite as

Entrainment of cold gas into thermal plasma jets

  • E. Pfender
  • J. Fincke
  • R. Spores
Article

Abstract

There is increasing evidence that the entrainment of cold gas surrounding a turbulent plasma jet is more of an engulfment type process rather than simple diffusion. A variety of diagnostic techniques have been employed to determine the development of turbulence in a plasma jet and to measure concentration and temperatures of the cold gas entrained into atmospheric-pressure argon plasma jets in ambient argon or air. The results indicate that the transition to turbulence causes a rapid drop of the axial jet velocity due to entrainment of the cold gas surrounding the plasma jet. Dissipation of the cold engulfed gas bubbles by molecular diffusion is relatively slow if molecular gases (for example air) are entrained, as indicated by conditional sampling and CARS measurements. Temperature measurements using emission spectroscopy and enthalpy probes show strong discrepancies in the jet fringes.

Key words

Thermal plasma jets cold gas entrainment diagnostics 

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Copyright information

© Plenum Publishing Corporation 1991

Authors and Affiliations

  • E. Pfender
    • 1
  • J. Fincke
    • 1
    • 2
  • R. Spores
    • 1
    • 3
  1. 1.Department of Mechanical Engineering and ERC for Plasma-Aided ManufacturingUniversity of MinnesotaMinneapolis
  2. 2.INEL, EG&G Idaho, Inc., Idaho Falls
  3. 3.Department of the Air Force, Air Force Phillips LaboratoryEdwards Air Force BaseCalifornia

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