Comparison between two- and three-dimensional diffusion models to describe wood drying at low temperature

An experiment on convective drying of lumber was performed at a temperature of 40 °C. A two-dimensional numerical solution of the diffusion equation with boundary condition of the third kind and variable effective mass diffusivity (model 1) was proposed to describe drying. The solution was coupled with an optimizer to determine the process parameters. The results were compared with those obtained by a typical three-dimensional numerical solution (model 2). The analyses of the results indicated that the parameters (and the simulation) obtained using model 1 are very close to the results obtained with model 2. However, the optimization time for model 1 is about 20 times less than the optimization time for model 2.