OH production by transient plasma and mechanism of flame ignition and propagation in quiescent methane-air mixtures

Journal Article · Mon Sep 15 00:00:00 EDT 2008 · Combustion and Flame

DOI:https://doi.org/10.1016/J.COMBUSTFLAME.2008.03.025· OSTI ID:21116078

Cathey, Charles; Cain, Jeremy; Wang, Hai; Gundersen, Martin A ^[1]; Carter, Campbell ^[2]; Ryan, Michael ^[3]

---

1. Department of Electrical Engineering-Electrophysics, University of Southern California, SSC 410, Seaver Science Center, 920 W. 37th Pl., Los Angeles, CA 90089-0271 (United States)
2. Air Force Research Laboratory, Wright-Patterson Air Force Base, OH 45433 (United States)
3. Universal Technology Corporation, Dayton, OH 45432 (United States)

Transient plasma induced production of OH is followed in a quiescent, stoichiometric CH{sub 4}-air mixture using the planar laser induced fluorescence technique. Ignition and subsequent flame propagation, for both the transient plasma and traditional spark ignition, are observed with a high speed camera (2000 fps). The transient plasma is generated using a 70 ns FWHM, 60 kV, 800 mJ pulse. OH production was confirmed throughout the chamber volume; however, the mean number density was found to decay below 1.3 x 10{sup 14}cm{sup -3} near 100 {mu}s. Nonetheless, ignition induced by transient plasma was decidedly faster than by spark ignition. Using the high speed camera, ignition initiated by transient plasma was found to occur along the length of the anode at approximately 1 ms, leading to the formation of a wrinkled, cylindrically-shaped flame. Analysis of the flame front propagation rates shows that flames ignited by transient plasma propagate essentially at the speed consistent with well accepted literature values for the stoichiometric methane-air mixture. This supports the notion that residue plasma, if any, has little effect on flame propagation. (author)

• OSTI ID: 21116078
• Journal Information: Combustion and Flame, Vol. 154, Issue 4; Other Information: Elsevier Ltd. All rights reserved; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
33 ADVANCED PROPULSION SYSTEMS
METHANE
AIR
PLASMA
MIXTURES
TRANSIENTS
IGNITION
FLAMES
VELOCITY
FLAME PROPAGATION
DENSITY
ELECTRIC SPARKS
STOICHIOMETRY
PULSES
RESIDUES
HYDROXYL RADICALS
INTERNAL COMBUSTION ENGINES
Transient plasma
Volumetric ignition
Transient plasma ignition
Planar laser induced fluorescence
High speed imaging