Experimental and Numerical Investigation of Heat and Mass Transfer during High-Temperature Thermal Treatment of Wood

Abstract

In this article, a three-dimensional mathematical model has been used to analyze the transient heat and moisture transfer during high thermal treatment of Aspen wood. The conservation equations for the wood sample are obtained using diffusion equation with variable diffusion coefficients and the three-dimensional incompressible Reynolds averaged Navier-Stokes equations have been solved for the flow field. Temperature distributions in wood and in gas as well as the moisture content of wood were measured during the experiments. Afterwards, hardness, modulus of elasticity, and modulus of rupture were measured. The experimental results and model predictions showed good agreement. Increasing heating rate is beneficial for the modulus of rupture and the modulus of elasticity heat treatment seems to increase for the range of parameters considered here. However, hardness of Aspen increases in the axial direction but does not change in the radial and tangential directions.

Keywords:

• CFD
• Heat and mass transfer
• High-temperature wood treatment
• Mechanical properties
• Validation

ACKNOWLEDGMENTS

The authors thank the University of Quebec at Chicoutimi (UQAC), the Foundation of the University (FUQAC), the Foundation Development Canada (DEC), the Consortium de Recherche sur la Forêt Boréale Commercial, Développement Économique, Innovation et Exportation (MDEIE), CRE, industrial partners, Forintek, and our research technician Jacques Allaire for their support and contributions.