Three-Dimensional (3D) Modeling of Heat and Mass Transfer during Microwave Drying of Potatoes

H. Zhu[1][2], T. Gulati[2], A. K. Datta[2], K. Huang[1]
[1]Institute of Applied Electromagnetics, Sichuan University, Chengdu, China
[2]Department of Biological and Environment Engineering, Cornell University, Ithaca, NY, USA

Microwave drying of fruits and vegetables in a domestic oven has been found to result in large textural changes in the product such as puffing, crack formation and even burning due to the inhomogeneous heating of the microwaves. Microwave drying of potatoes is a complex interplay of mass, momentum and energy transport. Three phases are considered in the system: solid (skeleton), liquid (water) and gas (water vapor and air). Concentration of different species was solved for using the Transport of Dilute Species module (for liquid water) and Maxwell-Stefan Diffusion model (for vapor and air) together with Darcy Law (to calculate Gas Pressure). Microwave oven worked in 10% power level (Cycle Way). Shrinkage effects have been ignored. The coupled Electromagnetic and Transport Model developed above was solved in COMSOL Multiphysics® 4.3a to obtain the moisture content and mass fraction of vapor.