Abstract
Effective thermal conductivity with contact resistance is analyzed by a homogenization method that can precisely represent the microstructure of a packed bed. The homogenization used in this study explains the heat transfer due to conduction through the solid, the fluid phase, and the contact area between particles, and radiation between solid surfaces. In particular, the effects of parameters, such as the hardness, contact pressure, roughness, temperature, and particle size of the packed bed, on conductivity are estimated in order to clarify the thermal conduction mechanism for the complex packed structure. Heat transfer with thermal contact resistance does not dominate if the Biot number is near 100. Moreover, thermal radiation in the bed becomes more important for larger particles (>1 mm) and contact resistance can be neglected.
