Investigation of water dissociation by Nanosecond Repetitively Pulsed Discharges in superheated steam at atmospheric pressure

Florent P. Sainct, Deanna A. Lacoste, Christophe O. Laux, Michael J. Kirkpatrick, Emmanuel Odic

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

5 Scopus citations

Abstract

Nanosecond Repetitively Pulsed (NRP) discharges in atmospheric pressure water vapor at 450 K are studied with time-resolved optical emission spectroscopy (OES). A 20-ns high- voltage pulse is applied across two pin-shaped electrodes at a frequency of 10 kHz, with an energy of 2 mJ per pulse. Emission of OH(A-X) as well as atomic states of O and H are observed. The emission of these species increases during the 20-ns pulse, then decreases. Then, after about 150 ns, we observe again a strong increase of emission of these species. To determine the gas temperature, we add a small amount (1%) of molecular nitrogen to the flow of water vapor. The rotational temperature measured from N2(C3IIu - B2IIg) second positive system of N2 is measured and compared with the rotational temperature measure with the OH(A-X) transition. The electron density is obtained by the Stark broadening of the Hβ emission line at 486 nm. The electron number density increases to about 6 × 1015cm-3 during the pulse, then decays to 1014cm-3 after 150 ns. But then, a surprising behavior occurs: the Full-Width at Half-Maximum (FWHM) of the Hβ emission line increases again sharply, with no electric field applied, up to 5 nm, and then decays slowly to 1 nm over the next microsecond.

Original languageEnglish (US)
Title of host publication51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 2013
StatePublished - 2013
Externally publishedYes
Event51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 2013 - Grapevine, TX, United States
Duration: Jan 7 2013Jan 10 2013

Other

Other51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 2013
CountryUnited States
CityGrapevine, TX
Period01/7/1301/10/13

ASJC Scopus subject areas

  • Space and Planetary Science
  • Aerospace Engineering

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