A CONTROL-VOLUME FINITE-ELEMENT NUMERICAL-SIMULATION OF THE HIGH-TEMPERATURE DRYING OF SPRUCE

Drying plays an important role in many industries as diverse as cement production to the manufacture of foodstuffs. In order to understand t he fundamental physics of the drying operation it is necessary to stud y the movement of moisture, in both the liquid and gaseous phases, thr oughout the capillary-porous body. The insight gained from the study c an lead, not only to a greater understanding of the phenomena which ar ise during drying, but also, to an increase in the efficiency and prod uctivity level of the kiln. Experimental methods enable drying practit ioners to gain only a limited insight, whereas, mathematical models ha ve been shown and proven to give a more detailed analysis of the dryin g process. This paper presents a novel application of the control volu me finite element numerical technique to simulate the high temperature drying of spruce. The numerical treatment of this problem has been st udied extensively in the past, however, the basic drawback with previo us numerical analyses is that they have been limited to a structured f ixed mesh. During drying, timber twists and distorts and to accurately model the drying procedure, it is essential that this behaviour is ta ken into consideration. The control volume finite element method enabl es a structured or unstructured mesh to be employed without alteration to the formulation, and lays the foundation for the simulation of the timber deformation.