Process of absorption and desorption of water in a wood board,with 3-dimensional transport beyond the FSP |
| |
Authors: | M El Kouali J Bouzon J M Vergnaud |
| |
Institution: | (1) Laboratoire de Chimie des Materiaux et Chimie Industrielle, Faculté des Sciences, Université de Saint-Etienne, 23 rue Docteur Paul Michelon, F-42100 Saint-Etienne, France |
| |
Abstract: | Summary The process of absorption of water in a piece of solid wood, as well as the following stage of desorption is studied, when the water content is beyond the fiber saturation point. A model based on a numerical method with finite differences is built and successfully tested. This model takes into account a 3-dimensional transport of water controlled by diffusion, with three principal axes of diffusion and three various principal diffusivities. The model is able to predict the kinetics of absorption or desorption when the three principal diffusivities are known, as well as the operational conditions.Symbols C (i, j, k)
Concentration at the position of the coordinates i, j, k and at the time t
- CN (i, j, k)
Concentration at the same position, at the time t + t
- Cs
Moisture content at the surface
- DL
Longitudinal diffusivity
- DT
Tangential diffusivity
- DR
Radial diffusivity
- L
Increment of space along the longitudinal axis
- T
Increment of space along the tangential axis
- R
Increment of space along the radial axis
- t
Increment of time
- EMC or Ceq
Moisture concentration at equilibrium
- K
Factor of evaporation (cm/s)
- L, T, R
Dimensions of the board along the longitudinal, tangential, radial directions, respectively
- ML
Dimensionless number for the longitudinal axis
- MT
Dimensionless number for the tangential axis
- MR
Dimensionless number for the radial axis
- Th
Thickness of a sheet (in Eq. 15) |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|