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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

EFFECTS OF MICRO-MORPHOLOGY ON BRDF OF SKELETON INSIDE METAL FOAM

Get access (open in a dialog) DOI: 10.1615/IHTC16.pma.023538
pages 8117-8125

Résumé

Metal foam is an attracting wide focus on thermal applications, such as high-temperature exchangers, solar receivers and so on. Radiative transfer is vital for the heat and mass transfer of metal foam. Radiative intensity is governed by the morphology of structures and their intrinsic radiative properties. The roughness is one of the principal factors influencing reflectance of skeleton's surface that takes place in the radiation heat transfer. The bidirectional reflectance distribution function (BRDF) is an important parameter to characteristic the radiative properties of skeletons' surface inside metal foam. This work is focused on the reflectivity and BRDF of metal open-cell foam and the effect made by the wavelength-scaled groove in the surface caused by the fabrication. For better characterization of the surface of skeleton in foam porous material, the SEM technique was adapted to analyze the morphology of surfaces. The width and irregular distribution mode were used to model the surface of metal skeleton. To get the radiative parameters of skeleton’s micro rough surface, the Finite-Difference Time-Domain (FDTD) technique was adapted to compute the reflectivity and BRDF of rough surface with groove i under the assumption of simplified model and period boundary. Furthermore, the radiative properties of regular and irregular structure of groove were compared, and the effect made by the incident light and carvings in surface including regularly and irregularly distributed were discussed, the results shows the different morphology of the skeleton in metal open-cell foam make effects on the radiative properties in various degree. The reflectivity and BRDF are effected by the various carvings.