Modeling conventional one-dimensional drying of radiata pine based on the effective diffusion coefficient

we modeled conventional one-dimensional drying of radiata pine (pinus radiata) wood using the concept of effective diffusion. the experimentally determined effective diffusion coefficients for the radial and tangential directions were related exponentially to the moisture content. these coefficients were characterized by two parameters that were determined through optimization within the context of an inverse problem. one-dimensional drying experiments were carried out under constant drying 44/36 (°c/°c) in order to determine transitory spatial distributions of moisture and drying curves, which were used then to determine the model parameters and validate the model. the mathematical model consisted of a partial, non-linear, differential equation of the second order and was characterized by coefficients that varied exponentially with moisture content; this later was integrated numerically through the finite volume method. simulations of the transitory distribution of moisture gradients gave satisfactory results, and the drying curves were correlated with experimental data as well as the values of the parameters required by the proposed model.