Microwave-Plasma-Coupled Re-Ignition of Methane-and-Oxygen Mixture Under Auto-Ignition Temperature

Abstract

The re-ignition phenomenon is observed when fuel/oxidizer is re-introduced into an atmospheric-pressure plasma discharge generated by cutting off the gas flow in a re-entrant microwave-plasma applicator system used for plasma-assisted ignition and combustion research works. Results indicate that, for re-ignition to occur, the electric field must be strong enough to fully establish a weakly ionized and self-sustained plasma discharge and with elevated radical concentrations. The re-ignition was possible at gas flow speeds higher than typical flame propagation rates, and temperature measurements (thermocouple and N2 emission) reveal that re-ignition occurs under auto-ignition temperatures. The high-speed imaging of the flame propagation shows that it is a two step process of initiating a fast pyrolysis flame, which, in turn, stabilizes and starts the direct coupling process of the plasma energy into the flame for full re-ignition to occur.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 2011
Accession Number
ADA560953

Entities

People

  • Campbell Carter
  • Jes Asmussen Jr.
  • Stephen D Hammack
  • T.A. Grotjohn
  • Tonghun Lee
  • Xing Rao

Organizations

  • Michigan State University

Tags

DTIC Thesaurus Topics

  • Air Force
  • Air Force Research Laboratories
  • Barometric Pressure
  • Chemical Reaction Properties
  • Chemistry
  • Combustion
  • Dissociation
  • Dye Lasers
  • Electric Fields
  • Flame Propagation
  • Gas Flow
  • Ignition
  • Laser Induced Fluorescence
  • Lasers
  • Measurement
  • Mechanical Engineering
  • Pyrolysis

Readers

  • Combustion science or combustion engineering.
  • Pulsed Power and Plasma Physics.