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Experimental study of the channel effect on the flame spread over thin solid fuels

We experimentally burn thin solid fuels and obtain the speed of the flame front when it propagates (1) within a narrow channel (closed cross section), (2) within a channel with lateral walls only and (3) through a free cross section (plain case). The latter configuration is the classical one and it has been extensively studied with analytical, numerical and experimental methods by other authors. Our experiments have been carried out at different geometrical configurations and angles of inclination of the sample and also at several values of oxygen molar fraction. All experiments are restricted to purely buoyant flow. Our main results are as follows: (1) sidewalls reduce the flame spread rate in a non-monotonous trend when varying its height; (2) in horizontal flame spread, two simultaneous flame fronts that propagate at different velocities may arise in the channel case at high oxygen levels. The fastest flame front speed may be higher than that obtained in the plain case; (3) in upward flame spread, the channel effect configuration produces the highest flame front speed. We finally analyze the correlation of the downward flame front speed data in terms of the Damkohler number

This work has been partially funded by the Generalitat de Catalunya under Grant 2009-SGR-374, the MICINN-FEDER under Grants FIS2009-13050 and FIS-2012-31307

漏 Fire Safety Journal, 2015, vol. 71, p. 162-173

Elsevier

Author: Comas Hervada, Bruna
Carmona Esparraguera, Adri脿
Pujol i Sagar贸, Toni
Date: 2015 January
Abstract: We experimentally burn thin solid fuels and obtain the speed of the flame front when it propagates (1) within a narrow channel (closed cross section), (2) within a channel with lateral walls only and (3) through a free cross section (plain case). The latter configuration is the classical one and it has been extensively studied with analytical, numerical and experimental methods by other authors. Our experiments have been carried out at different geometrical configurations and angles of inclination of the sample and also at several values of oxygen molar fraction. All experiments are restricted to purely buoyant flow. Our main results are as follows: (1) sidewalls reduce the flame spread rate in a non-monotonous trend when varying its height; (2) in horizontal flame spread, two simultaneous flame fronts that propagate at different velocities may arise in the channel case at high oxygen levels. The fastest flame front speed may be higher than that obtained in the plain case; (3) in upward flame spread, the channel effect configuration produces the highest flame front speed. We finally analyze the correlation of the downward flame front speed data in terms of the Damkohler number
This work has been partially funded by the Generalitat de Catalunya under Grant 2009-SGR-374, the MICINN-FEDER under Grants FIS2009-13050 and FIS-2012-31307
Format: application/pdf
ISSN: 0379-7112
Document access: http://hdl.handle.net/10256/14112
Language: eng
Publisher: Elsevier
Collection: MEC/PN 2010-2012/FIS 2009-13050
MICINN/PN 2013-2015/FIS2012-31307
Reproducci贸 digital del document publicat a: http://dx.doi.org/10.1016/j.firesaf.2014.12.001
Articles publicats (D-EMCI)
Is part of: 漏 Fire Safety Journal, 2015, vol. 71, p. 162-173
Rights: Tots els drets reservats
Subject: Combusti贸
Combustion
Combustibles
Fuel
Title: Experimental study of the channel effect on the flame spread over thin solid fuels
Type: info:eu-repo/semantics/article
Repository: DUGiDocs

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