Numerical Analysis of Heat–Mass Transport and Pressure Build-Up in 1D Unsaturated Porous Medium Subjected to a Combined Microwave and Vacuum System

Abstract

This article presents one-dimensional numerical analysis of heat-mass transport and pressure build-up inside an unsaturated porous media under microwave energy at a vacuum pressure condition. The unsaturated porous media is composed of glass beads, water, and air. The absorbed microwave power term is computed based on Lambert's law. The finite difference method together with Newton-Raphson technique is employed to predict the heat, multiphase flow, and pressure build-up. Based on the numerical analysis of the effects of vacuum pressure and types of dielectric materials, it was found that the vacuum pressure had a strong effect on temperature, absorbed microwave power, saturation and pressure build-up distribution, and movement of fluid inside the unsaturated porous media during the microwave drying process.