An experimental and numerical investigation of the microwave heating of wood

Research in wood heating and drying over the last few years has focused on the potential application of using microwave and radio-frequency energy in conjunction with conventional drying operations. Unfortunately, due to the complexity of the problem it is very difficult to investigate the evolution of the electromagnetic fields in a general microwave heating applicator using either experimental or analytical methods. In this paper, a previously developed mathematical model based upon a finite-volume time-domain (FVTD) formulation has been extended to enable the heating of an anisotropic material, such as wood, to be simulated in an arbitrarily shaped applicator. This comprehensive three-dimensional model will be validated against an extensive set of experimental results and used subsequently to investigate numerous aspects of the microwave heating of wood in a small scale industrial waveguide applicator. The agreement between the experimental and numerical simulation results highlights that the model can predict the microwave heating phenomena for an anisotropic material very accurately.