NUMERICAL AND EXPERIMENTAL FRACTAL PORE NETWORK STUDY ON THE DRYING OF POROUS MEDIA

Abstract

A fractal pore network model for unsteady drying process of a natural porous body is developed by applying knowledge on fractal geometry, physics of flow through porous media, and transportprocess principle, which takes various factors, such as liquid-phase flow, vapor-phase diffusion, temperature gradient, and pore microstructure characteristic, into consideration. The drying dynamics character of potato slices, as an example of a real porous body, is obtained by the simulations of both a fractal pore network model and a regular one. The simulation results indicate that the drying kinetics, as well as the distributions of moisture and temperature inside the porous body, from the fractal pore network model are more consistent with that from the drying experiment than that from the regular one. The wet patch appears during the simulation process and this similar contour is also observed on the potato slices in the experiments. The throat size distribution in pore network of the porous media affects the drying process dramatically during the simulations.