3D Modeling and Visualization of Non-Stationary Temperature Distribution during Heating of Frozen Wood

A 3-dimensional mathematical model has been developed, solved, and verified for the transient non-linear heat conduction in frozen and non-frozen wood with prismatic shape at arbitrary initial and boundary conditions encountered in practice. The model takes into account for the first time the fiber saturation point of each wood species, ufsp, and the impact of the temperature on ufsp of frozen and non-frozen wood, which are then used to compute the current values of the thermal and physical characteristics in each separate volume point of the material subjected to defrosting. This paper presents solutions of the model with the explicit form of the finite-difference method. Results of simulation investigation of the impact of frozen bound water, as well as of bound and free water, on 3D temperature distribution in the volume of beech and oak prisms with dimensions 0.4 x 0.4 x 0.8 m during their defrosting at the temperature of the processing medium of 80 oC are presented, analyzed and visualized through color contour plots.