Lawes, M, Sharpe, GJ, Tripathi, N et al. (1 more author) (2016) Influence of spark ignition in the determination of Markstein lengths using spherically expanding flames. Fuel, 186. pp. 579-586. ISSN 0016-2361
Abstract
Constant pressure outwardly propagating flame experiments in a spherical bomb are performed to examine the duration and radius over which spark ignition effects persist. This is motivated by the need to properly account for such effects in the measurement of laminar burning velocity and Markstein length using the spark ignited expanding flame technique. Ignition energy was varied and its effects on flame propagation in methane-air and isooctane-air mixtures were studied. The Markstein length of the mixture proved critical in the ignition energy dependency of flame propagation. For relatively high values, an underlying common variation of self-sustaining flame speed with radius can be identified by the rapid convergence of curves for different ignition energies. As the Markstein length decreases, low energy spark ignition is found to give rise to a distorted and wrinkled flame kernel. For such mixtures, due to the weak effect of stretch, the kernel subsequently develops into a non-spherically propagating flame. In these cases the spark ignition effect persists up to large radius. It is shown that using low ignition energy leads to a flame speed, during the development phase, which is higher than that of a self-sustaining spherical flame. It is further shown that if this effect is not accounted for, measurements of Markstein length using standard fitting techniques results in a large error. This problem is found to worsen as the Markstein length decreases, such that its apparent measured value becomes increasingly influenced by any distortions of the flame kernel produced by the spark.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2016, Elsevier. This is an author produced version of a paper published in Fuel. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Ignition; Laminar; Premixed; Flame wrinkling; Markstein length |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Mechanical Engineering (Leeds) > Institute of Engineering Thermofluids, Surfaces & Interfaces (iETSI) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 20 Sep 2016 14:08 |
Last Modified: | 28 Sep 2017 12:31 |
Published Version: | http://dx.doi.org/10.1016/j.fuel.2016.08.013 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.fuel.2016.08.013 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:104715 |