Prediction of the gaseous thermal conductivity in aerogels with non-uniform pore-size distribution

The gaseous thermal conductivity in nano-porous aerogel is an important contribution to the total thermal conductivity under normal temperature and pressure condition. Pore-size distribution in the aerogel has significant effect on the gaseous thermal conductivity. The pore-size in the porous materials generally presents random and non-uniform distribution, and large deviation will be caused if directly using the mean pore-size to calculate the gaseous thermal conductivity. We present a modified model based on the previous theoretical models to take into account the random and non-uniform pore-size distribution, and the predicted results from the present model are significantly better than those of existing models. (C) 2012 Elsevier B.V. All rights reserved.