Experimental characterization of the interaction between a radiation source and a semitransparent solid
Gregory T. Linteris, Nicolas Ball, J. Raynard, Jose L. Torero, P. Boulet, G. Parent, Z. Acem, M. Forsth
The sample-heater interaction for radiative heat transfer has been experimentally investigated for clear PolyMethylMethAcrylate (PMMA) samples with two different heaters (electric resistance and tungsten lamp). The significant impacts of the sample thickness and the heater (type and operating temperature) were revealed with broadband measurements of the ratio of transmitted heat flux through clear PMMA. These two aspects were then investigated more fundamentally with the spectral characterization of the attenuation coefficient (through Beer-Lamberts law) and the intensity emitted by both heaters. These two parameters are essential to predict accurately the in-depth absorption respectively in space and in magnitude. The attenuation coefficient, which presents large spectral heterogeneity, can be used to predict the evolution of the absorbance with the sample thickness as it is shown for independent measurements extracted from the literature. The measurements of the spectral intensity emitted by the heaters enable to reconsider the usual adopted assumption of blackbody behaviour. While the conical resistance behaves almost as a perfect blackbody, the tungsten lamp is even not behaving as grey body and a full characterization of its spectral intensity is required to capture its impact on pyrolysis. This investigation confirms the necessity of a multi-band model for the energy absorption of semi-transparent solid in pyrolysis model in order to capture accurately the temperature profile.
, Ball, N.
, Raynard, J.
, Torero, J.
, Boulet, P.
, Parent, G.
, , Z.
and , M.
Experimental characterization of the interaction between a radiation source and a semitransparent solid, Proceedings of the Combustion Institute
(Accessed December 10, 2023)