Predicting effective thermal conductivities of unbonded and bonded silica sands

A theoretical model to predict the effective thermal conductivities of unbo nded and bonded sands is developed by considering the relevant heat transfe r mechanisms and their relationship to the model geometry. Comparison betwe en model results and experimental measurements indicates that the assumptio ns leading to the introduction of two model parameters (phi(ef) and delta) were justified. As a result, the model was proved to predict the effective thermal conductivities of unbonded and bonded silica sands within reasonabl e accuracy and to estimate the effects of important parameters reasonably w ell. (C) 1999 American Institute of Physics. [S0021-8979(99)07421-6].