Spiral waves in expanding hydrogen-air flames: Experiment and theory

Document Type

Article

Publication Date

1-1-2007

Abstract

We report herein the first experimental observation of spiral waves over propagating flame surfaces in rich hydrogen-air mixtures at elevated pressures up to 40 atm, conducted in a specially designed, optically accessible, constant-pressure combustion chamber. The observed spiral waves are a manifestation of the large Lewis number instability, exhibiting behaviors such as clockwise/counterclockwise rotation, meandering, and fast radial wave speeds that are similar to patterns often observed in other excitable media, for example the Belousov-Zhabotinsky reaction. In addition, these spiral waves also exhibit features that seem to be characteristic of combustion systems, such as the transition criterion for diffusional-thermal pulsating instability, and their confinement within the hydrodynamic cells that also develop over such high-pressure flames of much reduced flame thicknesses. A diffusional-thermal theory was developed that successfully describes the observed spiral patterns. © 2006 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Identifier

34548768886 (Scopus)

Publication Title

Proceedings of the Combustion Institute

External Full Text Location

https://doi.org/10.1016/j.proci.2006.08.100

ISSN

15407489

First Page

1039

Last Page

1046

Issue

1

Volume

31 I

Fund Ref

National Aeronautics and Space Administration

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