Instantaneous flame anchor measurements behind a rearward-facing step

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The physical mechanisms governing flame anchoring have been examined in an effort to extend the range and maneuverability of compact, low-drag, air-breathing engines. Experiments were performed burning premixed methane and air in a planar dump combustor using reacting-flow particle image velocimetry as the primary diagnostic. Instantaneous two-dimensional images and vector fields were studied to determine changes in the fluid-chemical interactions of the shear layer as flame anchorability became more robust Conditional averages of combustion products directed toward incoming reactants were evaluated to establish the connection to self-sustained combustion. A lean mixture of methane-air was used as a baseline, and the equivalence ratio and near-field counterflow were varied to affect anchorability. Dilatation was calculated as a marker for heat release and threedimensionality. Operating points exhibiting a strong flux of products into reactants via a single coherent structure positioned downstream of the step were found to be most stable for flame anchoring. However, a counterflow level equal to 6.2% of the primary stream by mass was found to match the characteristics of a single coherent structure while maintaining multiple structures in the mixing zone, effectively increasing heat release rates at a lower equivalence ratio.

Original languageEnglish (US)
Pages (from-to)1350-1357
Number of pages8
JournalAIAA journal
Volume47
Issue number6
DOIs
StatePublished - Jun 1 2009

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Facings
Anchors
Methane
Air engines
Maneuverability
Air
Combustors
Velocity measurement
Drag
Fluxes
Fluids
Experiments
Hot Temperature

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Instantaneous flame anchor measurements behind a rearward-facing step. / Hoxie, Alison B; Lutz, J. M.; Strykowski, Paul J.

In: AIAA journal, Vol. 47, No. 6, 01.06.2009, p. 1350-1357.

Research output: Contribution to journalArticle

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