Effective structure of aerogels and decomposed contributions of its thermal conductivity

In this paper, a new effective model, Spherical hollow cube model, is proposed based on the structures. of aerogels and the prediction equation for the apparent thermal conductivity is theoretically derived. The effective thermal conductivity of different types of aerogels is estimated by the present model, and the predicted results are more agreeable with experimental data than that of the previous models. In addition, the thermal conductivity of two nano-porous materials at different gas pressure is investigated experimentally. The contributions of gas conduction, solid conduction and thermal radiation are obtained by decomposition method. (C) 2014 Elsevier Ltd. All rights reserved.