Investigation of intermittent microwave convective drying (IMCD) of food materials by a coupled 3D electromagnetics and multiphase model

Intermittent microwave convective drying (IMCD) improves energy efficiency and the product quality during drying of agricultural products. However, the physical mechanism of heat and mass transfer involved in IMCD is poorly understood due to lack of a comprehensive and realistic mathematical model of this process. A multiphase porous media model considering coupled electromagnetics and multiphase transport phenomena in porous media can potentially provide fundamental details of underlying mechanisms of IMCD. The aim of this study is to develop a mathematical model for IMCD considering electromagnetics using Maxwell's equations coupled with multiphase porous media in 3D and validate the model against experimental results. The results show that the temperature distribution is uneven in the material, which redistributes during the tempering period. The water and vapor fluxes showed asymmetric profile along the diameter of the sample due to the non-uniformity of microwave heating. A clear understanding of these transport mechanisms in IMCD will lead to the development of appropriate drying process for improved food quality, energy efficiency, and optimization of the IMCD process.