Simultaneous moisture transport and shrinkage during drying of parallelepiped solids

A three-dimensional mathematical model to describe the unsteady state diffusion phenomenon including shrinkage applied to solids parallelepiped is presented. The model assumes to be constant thermo-physical properties and convective boundary conditions at the surface of the solid. The governing equations are solved using the finite-volume method and fully implicit formulation. As application the model was used to describe the drying of a ceramics brick. To validate the methodology, numerical results of the moisture content along the drying process are compared with analytical data reported in the literature. A good agreement was obtained. Other results of the moisture content distribution are shown and analyzed. The knowledge of moisture content distribution inside the material allows verifying more favorable areas to thermal stress, cracks and deformations. This manner is possible to optimize the drying process and to increase the quality of the product in the end of the process.