Thermal conduction of multi-phase systems at normal and different interstitial air pressures

The technique developed by Pande and Chaudhary (1984) to estimate the effective thermal conductivity (ETC) of loose two-phase systems, assuming an effective continuous medium (ECM), is extended to loose multi-phase systems at normal pressure. By considering the thermal conduction through molecular collisions, an expression for the ETC of loose multi-phase systems at interstitial air pressures is developed in terms of the characteristic pressure P c . To test the validity of the derived expression, experimental measurements on the ETC of multi-phase porous systems have been carried out at normal and different interstitial air pressures employing a thermal probe. A good agreement was found between the determined and the predicted values.