Transient Plasma Induced Production of OH and its Effects on Ignition in Atmospheric CH4-AIR Quiescent Mixtures (Postprint)
Abstract
Transient plasma from a 60 kV, 70 ns pulse induced OH production in air and CH4/air quiescent mixtures inside a cylindrical chamber is analyzed. The resulting OH from the plasma discharge, ignition, and subsequent combustion is analyzed using planar laser induced fluorescence. A high-framing-rate camera was also used to image ignition and flame propagation in the chamber, providing spatial and temporal resolution over the entire combustion event. Results indicate OH structures produced during the discharge in humid, ambient air are less branched, thicker, and last longer when compared to structures in CH4/dry-air. Transient plasma successfully ignited the CH4/air mixture, populating the discharge volume with radicals. Mean OH number densities produced by the discharge were found to decay within 100 s of the plasma. Ignition under these conditions was found to occur approximately 1 ms after the discharge along the anode, creating multiple ignition kernels whose proximity to the anode is consistent with the region of highest field and, thus, maximum radical density.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2008
- Accession Number
- ADA478541
Entities
People
- Campbell D. Carter
- Charles Cathey
- Hai Wang
- Jeremy Cain
- Martin A. Gundersen
- Michael Ryan
Organizations
- Air Force Research Laboratory