Modeling unsteady heat and mass transfer with prediction of mechanical stresses in wood drying

• Published in: International communications in heat and mass transfer 2021-04, Vol.123, p.105230, Article 105230
• Main Authors: Chávez, Cristian A., Moraga, Nelson O., Salinas, Carlos H., Cabrales, Roberto C., Ananías, Rubén A.
• Format: Article
• Language: English
• Subjects: Coupled heat and mass transfer; Pinus radiata; Shrinkage; Stress-strain; Wood drying
• ISSN: 0735-1933; 1879-0178
• DOI: 10.1016/j.icheatmasstransfer.2021.105230

This work presents a predictive transient two-dimensional model describing the evolution of heat, mass and mechanical stresses during wood dehydration inside an experimental drying chamber. The history of the distributions of moisture content and temperature and the effects produced by its gradients on the stresses were simultaneously modeled. The non-linear coupled differential equations of heat, mass and stresses were integrated by the Control Volume Finite Element method using triangular elements with linear interpolation functions for the dependent variables. Variation of the physical and mechanical properties with the moisture content and temperature in the wet wood were included in the analysis. Experimental results of Pinus radiata being dried inside a conditioned chamber at constant air velocity equal to 1.6 m/s, 44 °C dry-bulb and 36 °C wet-bulb temperatures were used for validation purposes. The mathematical model allows an accurate prediction of the relevant industrial information, such as: drying curves, evolution of temperature distribution, history of moisture content distribution and mass/thermal stresses. •Unsteady model for heat and mas transfer with prediction of stresses during wood drying process.•Numerical results of heat and mass diffusion and drying stresses were validated with experimental data with satisfactory results.•The equations of transport of mass, energy and mechanics of solids were successfully coupled