A bifurcation analysis of high-temperature ignition of H2-O2 diffusion flames

Sánchez Pérez, Antonio Luis and Liñán Martínez, Amable and Williams, F.A. (1994). A bifurcation analysis of high-temperature ignition of H2-O2 diffusion flames. In: "Symposium (International) on Combustion (25. 1994. Irvine, California)", 31 Jul - 5 Ago 1994, Irvine, California. ISBN 0082-0784.

Description

Title: A bifurcation analysis of high-temperature ignition of H2-O2 diffusion flames
Author/s:
  • Sánchez Pérez, Antonio Luis
  • Liñán Martínez, Amable
  • Williams, F.A.
Item Type: Presentation at Congress or Conference (Article)
Event Title: Symposium (International) on Combustion (25. 1994. Irvine, California)
Event Dates: 31 Jul - 5 Ago 1994
Event Location: Irvine, California
Title of Book: Twenty-Fifth Symposium (International) on Combustion
Date: 1994
ISBN: 0082-0784
Subjects:
Faculty: E.T.S.I. Aeronáuticos (UPM)
Department: Motopropulsión y Termofluidodinámica [hasta 2014]
Creative Commons Licenses: Recognition - No derivative works - Non commercial

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Abstract

The form of the ignition branch for steady, counterflow, hydrogen-oxygen diffusion flames, with dilution permitted in both streams, is investigated for two-step reduced chemistry by methods of bifurcation theory. Attention is restricted to fuel-stream temperatures less than or equal to the oxidizer-stream temperature Tx and to T„ larger than or of the order of the crossover temperature Tc at which the rates of production and consumption of H atoms are equal. Two types of solutions are identified, a frozen solution that always exists in this kinetic approximation because all rates are proportional to the concentration of the intermedíate H atom, and an ignited solution, represented by a branch of the curve giving the máximum H concentration in terms of a Damkohler number constructed from the strain rate and the rate of the branching step H + Os - OH + O. For T„ > T„ the latter bifurcates from the frozen solution if the Damkohler number is increased to a critical valué. For T„ larger than a valué Ts > Tc, the effeets of chemical heat reléase are small, and ignition is always gradual in the sense that the limiting ignited-branch slope is positive (supercritical bifurcation) and there is no S curve. For T„ in the range Tc< T„ < T„ the heat reléase associated with the radical-consumption step causes the limiting ignition-branch slope to become negative (subcritical bifurcation), producing abrupt ignition which leads to an S curve. For valúes of Tx below crossover, the ignited branch appears as a C-shaped curve unconnected to the frozen solution. The method of analysis introduced here offers a first step toward analytical description of nonpremixed H2-02 autoignition.

More information

Item ID: 1295
DC Identifier: http://oa.upm.es/1295/
OAI Identifier: oai:oa.upm.es:1295
Deposited by: Biblioteca ETSI Aeronauticos
Deposited on: 12 Jan 2009
Last Modified: 20 Apr 2016 06:46
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