An analytical solution to coupled heat and moisture diffusion transfer in porous materials

An analytical method is proposed for solving the problem of coupled heat an d moisture transfer in porous materials. The coupled partial differential e quations and boundary conditions are first subjected to Laplace transformat ion, the equations are reduced to ordinary differential equations, then the equations are converted into a single fourth-order ordinary differential e quation by introducing a transformation function. The solution of the equat ion can be easily obtained, and thus, the temperature and moisture distribu tions in the transform domain can be determined. Finally, the transformed v alues are analytically or numerically inverted to obtain the rime domain re sults. Therefore, the transient solution at any given time can be evaluated . The results are identical with published analytical solutions for a speci al case using decoupling technique, and they agree with a published analyti cal solution for wood slab. The method is compact enough to be generally ap plied to problems of heat and mass transfer in porous media. (C) 2000 Elsev ier Science Ltd. All rights reserved.