Analysis of Heat–Mass Transport and Pressure Buildup Induced inside Unsaturated Porous Media Subjected to Microwave Energy Using a Single (TE10) Mode Cavity

This article presents the two-dimensional numerical analysis of heat and mass transport and pressure built up inside an unsaturated porous packed bed under microwave energy at a frequency of 2.45 GHz using a rectangular waveguide (TE10 mode). The unsaturated porous packed beds were composed by glass beads, water, and air. The samples were prepared by compacting uniformly with various thicknesses δ = 30, 50, and 80 mm and particle sizes d = 0.15 mm (fine packed bed) and 0.4 mm (coarse packed bed), respectively. A proposed model used to investigate heat–mass transport and pressure buildup phenomena inside the porous packed bed in which the rectangular waveguide with varying glass bead sizes and sample thicknesses was inserted. The results show that the effect of particle sizes and thicknesses of porous packed bed are primary factors determining heat and mass transport with multiphase flow. These findings can explain the phenomena taking place inside unsaturated porous media in a microwave drying process using a rectangular waveguide.