A new cool flame: Establishment and studies of dynamics and kinetics

Sang Hee Won, Bo Jiang, Pascal Diévart, Yiguang Ju, Chae Hoon Sohn

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations

Abstract

A novel method to establish self-sustaining cool diffusion flames with well-defined boundary conditions has been experimentally demonstrated by using ozone into the oxidizer stream in counterflow configuration. It is found that the formation of atomic oxygen via the decomposition of ozone dramatically shortens the induction timescale of low temperature chemistry, extending the flammable region of cool flames, and enables the establishment of self-sustaining cool flames at pressure and timescales at which normal cool flames may not be observable. The present method, for the first time, provides an opportunity to study cool flame dynamics, structure, and chemistry simultaneously in well-known flame geometry. Extinction limits of n-heptane/oyxgen cool diffusion flames are measured. A cool diffusion flame diagram for four different flame regimes is experimentally measured. Numerical simulations show that the extinction limits of cool diffusion flames are strongly governed by species transport and low temperature chemistry activated by ozone decomposition. The structure of cool diffusion flame is further investigated by measuring the temperature and species distributions with a micro-probe sampling technique. It is found that the model overpredicts the rate of n-heptane oxidation, the heat release rate, and the flame temperature. Measurements of intermediate species, such as CH2O, acetaldehyde, C2H4, and CH4 indicate that the model over-predicts the QOOH thermal decomposition reactions to form olefins, resulting in substantial over-estimation of C2H4, and CH4 concentrations. The new method and data of the present study will contribute to promote understandings of cool flame chemistry.

Original languageEnglish (US)
Title of host publication52nd AIAA Aerospace Sciences Meeting - AIAA Science and Technology Forum and Exposition, SciTech 2014
PublisherAmerican Institute of Aeronautics and Astronautics Inc.
ISBN (Print)9781624102561
DOIs
StatePublished - 2014
Event52nd AIAA Aerospace Sciences Meeting - AIAA Science and Technology Forum and Exposition, SciTech 2014 - National Harbor, MD, United States
Duration: Jan 13 2014Jan 17 2014

Publication series

Name52nd AIAA Aerospace Sciences Meeting - AIAA Science and Technology Forum and Exposition, SciTech 2014

Other

Other52nd AIAA Aerospace Sciences Meeting - AIAA Science and Technology Forum and Exposition, SciTech 2014
CountryUnited States
CityNational Harbor, MD
Period1/13/141/17/14

All Science Journal Classification (ASJC) codes

  • Space and Planetary Science
  • Aerospace Engineering

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    Won, S. H., Jiang, B., Diévart, P., Ju, Y., & Sohn, C. H. (2014). A new cool flame: Establishment and studies of dynamics and kinetics. In 52nd AIAA Aerospace Sciences Meeting - AIAA Science and Technology Forum and Exposition, SciTech 2014 (52nd AIAA Aerospace Sciences Meeting - AIAA Science and Technology Forum and Exposition, SciTech 2014). American Institute of Aeronautics and Astronautics Inc.. https://doi.org/10.2514/6.2014-0818