NUMERICAL INVESTIGATION OF HEAT TRANSFER THROUGH POROUS MEDIA

Abstract

Heat transfer mechanism model was predicted in order to simulate the temperature distribution of the two phases (glass-air) through the macrostructure of porous media sample in depth 20 mm at local equilibrium. It has been heating the sample from left side through x-axis with different values of heat flux. The model contain two stages: firstly, predict the temperature distribution in solid phase by transient 2-dimensional conduction heat equation; secondly, switching was happened in the program to simulate the temperature distribution in fluid phase of sample by energy balance. It has been found the temperature distribution in glass and air through the first two layers of series configuration of the sample. It showed very small values of heat transfer coefficient between these layers. That means high insulation property was observed from this structure of porous media sample. Due to the heating process, it has been noted the air inside the first layer was accelerated a very little bit as marks the onset of convection. This is due to the pressure gradient was produced between the outside and inside layers of sample through heating process with time. Darcy law was used to calculate this air velocity. Heat transfer coefficient inside porous media, effective Nusslet number and Nusslet number of fluid phase were calculated.