A two-dimensional study of wood plank drying. The effect of gaseous pressure below boiling point

This study is specially focused on the internal gaseous pressure of a plank of softwood, during drying below boiling point.The one-dimensional numerical study shows a depression inside the plank, which depends on permeability and initial saturation. With the two-dimensional numerical study, one notices a reduction in this depression. As the longitudinal permeability is much greater than the transversal one (radial or tangential), the air flow can more easily fill the water volume evacuated. The simulation exhibits displacement of drying fronts from the transversal faces and extremities. As the exchange area of the extremities is weak, the two-dimensional effect is limited to a specific distance. The coefficients of the model are issued from literature.An experimental study confirms the progression of the moisture field. The moisture profiles are obtained by conductivity measurements between needles. The improvement of two-dimensional drying can be evaluated using drying kinetics.