Numerical Computational Method for Wood Drying

A mathematical modeling for the drying process of hygroscopic porous media, such as wood, has been developed in the past decades. The governing equations for wood drying consist of three conservation equations with respect to the three state variables, moisture content, tem-perature and air density. They are involving simultaneous, highly coupled heat and mass trans-fer phenomena. In recent, the equations were extended to account for material heterogeneity through the density of the wood and via the density variation of the material process, capillary pressure, absolute permeability, bound liquid diffusivity and effective thermal conductivity. In this paper, we calculate the three primary variables of the drying process in terms of control volume finite element method to the heterogeneous transport model on unstructured grid. MATHEMATICAL MODELLING We introduced the mathematical formulation which represents the process of the wood drying, based on the model developed by Whitaker [7] and later by Perre ́ and Turner [3]. The equations were extended to account for material heterogeneity through the density of the wood and via density variation of the material properties, capillary pressure, absolute permeability, bound liquid diffusivity and effective thermal conductivity. The system of the three governing equations is summarized as follows