Quantitative evaluation of the effective thermal conductivity of porous media has received wide attention in science and engineering since it is a key thermophysical parameter in characterizing heat transfer properties. Based on fractal characters of tortuous capillary tubes and rough surfaces in micro-pores, we proposed a theoretical model of the effective thermal conductivity in porous media with rough surfaces. This model considers the geometrical parameters of porous media, including porosity, micro-pore fractal dimension, tortuosity fractal dimension, and relative roughness. The calculated normalized effective thermal conductivity was then validated against published experimental data. The results show good agreement between them. The influence of geometrical factors, porosity and relative surface roughness, on the effective thermal conductivity in porous media with rough surfaces are discussed and analyzed extensively.
Bibliographical noteFunding Information:
This project was supported by the National Natural Science Foundation of China (No. 41572116), and the Hubei Provincial Natural Science Foundation of China (No. 2018CFA051). Dr. Zhou would like to thank the Royal Society to support his trip to China with the International Exchange Programme and Mr. Qin would like to thanks the British Council and China Scholarship Council to support his stay at the University of Aberdeen through the UK-China PhD Placement Programme.
© The Author(s) 2019.
- Effective thermal conductivity
- Porous media
- Rough surfaces