CONVECTIVE HEAT AND MASS-TRANSFER IN NONISOTHERMAL MOISTURE DESORPTION

The effect of forced convective heat and mass transfer coefficients on the predictive ability of a dynamic nonisothermal set of coupled partial differential equations was investigated. Two forms of the temperature gradient coefficient in the mass conservation equation of the model were used. The predictability of the transient average moisture and temperature of a wood specimen under nonisothermal desorption conditions as evaluated for the two coefficient forms and for various values of the heat and moisture convective coefficients. The analysis showed that the model using the simplest form of the two coefficients, resulted in a very good prediction of the experimental data, and that the moisture-time and temperature-time curves, were strongly affected by the values of the two convective coefficients. Finally, a method to determine the optimum values of the two convective coefficients is suggested.