Abstract
In the present work we aim to simulate unsteady two-dimensional evolution of the moisture content, temperature and mechanical stress in a parallelepiped apple sample during convective drying. The model is based on the heat and mass transfer equations and the mechanical equilibrium equation under the assumptions of plane deformation, viscoelasticity and isotropic hydric shrinkage. The Finite Elements COMSOL Multiphysics solver is used to solve the developed model. The hydro-thermal model was validated on experimental data drawn in our laboratory for moisture and temperature internal profiles of the product. Excellent agreement has been obtained between numerical and measured data for different drying temperatures. The hydro-thermal model was, then, implemented in a Finite Element hydro-thermo-viscoelastic developed model. Results for mechanical stresses are found to be in good agreement with former observations. It was found, also, that the maximum stress arises at the beginning of drying and holds at the top external surface of the sample which is the surface facing the airflow. The phenomenon is augmented by temperature.