Measurements of Combustion Properties in a Microwave Enhanced Flame (Postprint)

Abstract

Microwave induced flame speed enhancement is quantified in a laminar, premixed CH4/air wall stagnation flat flame. Experiments were performed in a high Q microwave cavity with the cavity tuned so that the maximum microwave field is located in the vicinity of a flat flame front. Equivalence ratios were varied between 0.6 and 0.8. When the flame is radiated by a continuous wave microwave field of approximately 5 kV/cm, the flame front is observed to move towards the burner exit and stabilize at a standoff distance corresponding to a flame speed increase of up to 20%. No microwave discharge is observed, indicating that the enhanced flame speed arises from microwave energy deposited directly into the reaction zone through coupling to the weakly ionized gas in that region. Laser diagnostics were performed to quantify temperature increase, the laminar flame speed enhancement, and changes in the OH radical concentration through filtered Rayleigh scattering, particle image velocimetry, and planar laser induced fluorescence, respectively.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 2010
Accession Number
ADA516720

Entities

People

  • Campbell D. Carter
  • Emanuel S. Stockman
  • Michael D. Ryan
  • Richard B. Miles
  • Sohail H. Zaidi

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies
  • Space

DTIC Thesaurus Topics

  • Accuracy
  • Air Force
  • Air Force Research Laboratories
  • Chemical Reactions
  • Combustion
  • Electromagnetic Scattering
  • Electrons
  • Flow
  • Fluorescence
  • Frequency
  • Gases
  • Laser Diagnostics
  • Laser Induced Fluorescence
  • Lasers
  • Measurement
  • Radiation
  • Scattering

Fields of Study

  • Physics

Readers

  • Combustion science or combustion engineering.
  • Fluid Mechanics and Fluid Dynamics.
  • Plasma Physics / Magnetohydrodynamics

Technology Areas

  • Directed Energy