Optical and radiative properties of clear \PMMA\ samples exposed to a radiant heat flux

Abstract : Radiative transfer through clear \PMMA\ samples subjected to a constant radiant heat flux was studied. The aims of the present study were threefold. First, optical indices of clear \PMMA\ were determined from reflectivity and transmissivity measurements. Clear \PMMA\ exhibits a strong non-grey behavior, quite transparent in the visible and near infrared ranges of the spectrum, and almost opaque in some bands of the mid infrared. Absorption and refraction indices were obtained using an identification method applied to the transmissivity data of several samples with different thicknesses whenever possible (i.e. in ranges with sufficiently high transmission levels), whereas elsewhere, the Lorentz oscillators model coupled with a genetic algorithm was applied to the reflectivity data. Secondly, the absorption coefficient was determined at a very fine resolution of 4 cm−1. A nineteen-band model was proposed to represent the spectral variation of the absorption coefficient in the range of [590–18999 cm−1]. Third, a reciprocal Monte Carlo simulation was performed to calculate the response of a 3-cm-thick \PMMA\ sample to a 18 kW m−2 externally incident radiation, involving absorption and internal emission into the solid. Radiative transfer, pure or combined with conduction and convection, was considered to simulate the early stages of sample heating (before the glass transition of PMMA) from two different radiative sources, namely a cone calorimeter and a tungsten lamp. The influence of the type of the radiation source was clearly demonstrated in terms of temperature distribution inside the material and divergence of the radiative flux. All input data (optical and radiative properties) are available upon request to the corresponding author.
Type de document :
Article dans une revue
International Journal of Thermal Sciences, Elsevier, 2014, 82, pp.1 - 8. 〈10.1016/j.ijthermalsci.2014.03.013〉
Liste complète des métadonnées

https://hal.univ-lorraine.fr/hal-01425192
Contributeur : Lemta Ul <>
Soumis le : mardi 3 janvier 2017 - 14:05:59
Dernière modification le : jeudi 18 janvier 2018 - 01:27:04

Identifiants

Collections

Citation

Pascal Boulet, Jonathan Gerardin, Zoubir Acem, Gilles Parent, Anthony Collin, et al.. Optical and radiative properties of clear \PMMA\ samples exposed to a radiant heat flux. International Journal of Thermal Sciences, Elsevier, 2014, 82, pp.1 - 8. 〈10.1016/j.ijthermalsci.2014.03.013〉. 〈hal-01425192〉

Partager

Métriques

Consultations de la notice

42