; Zhang, Meijie
; Gu, H.
; Huang, A.
The Influence of Thermal Radiation on Effective Thermal Conductivity
in Porous Material
Interceram 65 (2016)  237-243
Effective thermal conductivity is an important parameter of
porous materials for measurement of heat insulation
performance. Two-dimensional geometrical models based on
micrographs of real material were constructed in this paper and
the finite element approach was applied for thermal analysis, the
effective thermal conductivity was calculated. The influence of
radiation heat transfer, temperature, and porosity on thermal
conductivity were analyzed. The results show that conduction
heat transfer plays an important role in total heat transfer and
the influence of radiation heat transfer was small at low
temperature. Because of the increase in radiation heat transfer,
the temperature gradient decreased obviously at high
temperature and the heat flux lines passed through the pores and
became relatively smooth; thus the radiation heat transfer plays
an important role in total heat transfer at high temperature and
the influence of radiation heat transfer cannot be ignored.
Thermal conductivity for a high porosity value will be greater
than thermal conductivity for a low porosity value at high
temperature. This paper provides guidance for predicting
thermal conductivity and reducing the heat transfer efficiency of
porous materials at high temperature.
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