Nonsymmetrical drying tests--Experimental and numerical results for free and constrained spruce samples

The paper brings new insights into nonsymmetrical convective drying, a configuration in which stresses induce a global change of the section shape of a wooden board with five insulated faces. Two experimental devices that allow to test simultaneously "twin" wooden boards have been developed: the first board is free and its curvature is collected vs. time; the second one is constrained and the force required to keep it flat is collected vs. time. Convective drying tests have been performed on radial specimens of spruce, 5 and 15 mm thick at 45 and 65°C. The results are commented and compared with simulation runs. For this purpose, a 1-D mechanical formulation is embedded in the computational code of heat and mass transfer TransPore. The objective of the comparison between numerical and experimental results is a better understanding of the coupled phenomena and the identification of some transfer and mechanical parameters.