The effects of gas-phase and in-depth radiation absorption on ignition and steady burning rate of PMMA

Abstract

Article:Staggs, J (2014) The effects of gas-phase and in-depth radiation absorption on ignition and steady burning rate of PMMA. Combustion and Flame, 161 (12 ReuseUnless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request.

Large eddy simulation of upward flame spread on PMMA walls with a fully coupled fluid–solid approach

“…Some previous studies considered incident radiative heat flux only at the surface [14], and converted it to the heat fluxes into the solid phase. While some other studies suggested that in-depth radiation causes ignition delay [44,45]. The authors believe it should be taken into account.…”

“…It would be outside the scope of the present study to resolve these issues, which can be revisited later when such information/data is available. In the present study, only absorption was accounted for by Beer's law [3,44,45] and radiative emissivity inside the PMMA was neglected. The heat flux of in-depth radiation q dep due to absorption can be written as below using Beer's law :…”

Effects of Combined Surface and In‐Depth Absorption on Ignition of PMMA

“…Additionally, Staggs [ 27 ] proposed the following formulation to qualitatively estimate the effects of in-depth absorption on ignition: which indicates that will reduce in direct proportion to .…”

“…Moreover, it was also found that in-depth absorption exists even for the presence of coated carbon black on the surface. Bal [ 19 ] and Staggs [ 27 ] numerically investigated the ignition behaviors of PMMA considering both surface and in-depth absorption, and an optimized combination was suggested. Also, it was found that the traditional coating of black carbon added on the sample does not cancel in-depth radiation absorption but rather its effect is to absorb around 35% of the incoming radiation at the surface.…”

Important Parameter Groups in Thermal Protection of Polymers

“…Recent contributions on ignition at high incident heat flux [ 18 , 19 ], have shown that for infra-red heat sources the ignition time—heat flux dependence predicted by Equation (8) above is reliable only for moderate heat fluxes up to ~40 kWm −2 , particularly for PMMA. At higher heat flux, it appears that infra-red absorptivity has a significant effect on ignition time and that observed ignition resistance is actually greater than that predicted by the simple theory above.…”