Library Subscription: Guest
Begell Digital Portal Begell Digital Library eBooks Journals References & Proceedings Research Collections
Special Topics & Reviews in Porous Media: An International Journal
ESCI SJR: 0.376 SNIP: 0.466 CiteScore™: 0.83

ISSN Print: 2151-4798
ISSN Online: 2151-562X

Special Topics & Reviews in Porous Media: An International Journal

DOI: 10.1615/SpecialTopicsRevPorousMedia.v2.i4.10
pages 249-265

MODELING OF THE COUPLED CONDUCTIVE AND RADIATIVE HEAT TRANSFER IN NICRAL FROM PHOTOTHERMAL MEASUREMENTS AND X-RAY TOMOGRAPHY

Dominique Baillis
LaMCoS, INSA-Lyon, CNRS UMR 5259,18-20 Rue des Sciences, F69621 Villeurbanne, France
Remi Coquard
Société "Etude Conseils Calcul Modélisation" (EC2-MODELISATION), 66 Boulevard Niels Bohr, F69603 Villeurbanne, France
D. Rochais
Commissariat à l'Energie Atomique/Le Ripault, F-37260 Monts, France

ABSTRACT

The present study proposes a complex and sophisticated model of prediction of the heat transfer through NiCrAl foams. The model developed takes into account the coupled conductive-radiative transfer and uses cutting-edge techniques for the characterization of the porous morphology of the foam and for the estimation of the intrinsic conductive and optical properties of the solid phase. Indeed, the equivalent spectral radiative properties and the effective conductivities are determined from 3-D X-ray tomographic images of several foam samples using time-tested numerical models, while the variations of the thermal conductivity of the NiCrAl solid phase with temperature are measured by a newly developed microscopic photothermal technique. The properties estimated numerically are used to investigate the evolution of the total heat transfer, that is, the equivalent thermal conductivity of the foam samples with the temperature. The results obtained are compared with predictions given by analytical correlations of the literature which neglect radiation-conduction coupling and use the Rosseland approximation to treat the radiative heat transfer. The results of the analytical correlations prove to be quite satisfactory. The numerical model is also validated by comparing with experimental results. The agreement is globally satisfactory.