Natural Convection in the Saturated Packed Bed around a Horizontal Cylinder with a Periodically Heated Wall

Abstract

Unsteady state natural convection around a horizontal cylinder in the saturated-glass-beads packed bed is experimentally and numerically investigated. The outside wall-temperature changes sinusoidally to clarify periodical temperature changes in the packed bed in Darcy and non-Darcy flows. For Darcy flow regions, clear thermally concentrated regions appear periodically in the porous media for rather large periodic time, but they are unclear for non-Darcy flows. This phenomenon is successfully analyzed based on the Forchheimer-Brinkman-Boussinesq model. Also, good agreement is obtained in consideration of the thermal nonequilibrium between particles and surrounding fluids and the channel effects near the cylinder wall with large particles.