A 3-Dimensional Body Fitted Simulation of Heat and Mass Transfer in Rice Kernel during Hot Air Drying Process

Abstract

Abstract A precise geometry model of the rice kernel is necessary to predict the moisture content and temperature distribution, or even drying stress in the kernel. In this study, a three-dimensional body fitted model of brown rice (Chunyou 84) kernel was developed by using image processing method, and the COMSOL Multiphysics software was used to simulate the drying process of the brown rice and compared with the experimental results. The maximum deviation between the simulated and experimental results was about 8%. During the drying process, the temperature gradient in the rice kernel only occurred a few minutes at the initial drying period (0–6.5 min, at 45 °C), while the moisture content gradient lasted in the whole drying process. Simulation and experimental results showed that the hot air temperature was one main factor governing the drying process of the brown rice.