Application of simultaneous heat, mass, and pressure transfer equations to timber drying

A set of coupled heat, mass, and pressure transfer equations proposed by Luikov [1] was employed to model the heat, mass, and pressure transfer phenomenon in a capillary porous body. A two-dimensional finite element model was formulated to solve the system of equations. The simulated results agreed well with the exact solutions. The finite element model was then used to study the sensitivity of the parameters in Luikov's heat, mass, and pressure transfer system and to estimate the key parameters identified (the thermal conductivity k_q and the coefficient of moisture conductivity k_m) for Norway spruce. The two-dimensional finite element model was further used to predict the temperature, moisture, and pressure variation during drying of Norway spruce. The mass average moisture content and temperature at the geometric center of a Norway spruce sample were measured at different drying temperatures. The predicted results agreed very well with the experimental results for all of the drying conditions considered.