The use of a coupled computational model for studying the microwave heating of wood

Citation
H. Zhao et Iw. Turner, The use of a coupled computational model for studying the microwave heating of wood, APPL MATH M, 24(3), 2000, pp. 183-197
Citations number
21
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Engineering Mathematics
Journal title
APPLIED MATHEMATICAL MODELLING
ISSN journal
0307-904X → ACNP
Volume
24
Issue
3
Year of publication
2000
Pages
183 - 197
Database
ISI
SICI code
0307-904X(200003)24:3<183:TUOACC>2.0.ZU;2-N
Abstract
This paper presents a three-dimensional computational model for the microwa ve heating of wood with low moisture contents. The model couples an existin g finite-volume time-domain algorithm (FVTD) for resolving Maxwell's equati ons on arbitrary shaped domains, together with an algorithm for determining the thermal distribution within the wood sample. This complex nonlinear he ating process is tightly coupled - small changes in the dielectric properti es, which depend on the thermal field within the material, can induce signi ficant changes in the power distribution and, conversely, small changes in the power distribution can impact substantially upon the temperature distri bution. The objective of this paper is to provide a detailed algorithm for the numerical treatment of this nonlinear process. In particular, an estima te of the total number of periods necessary for the power distribution to a ttain its steady-state will be determined so that the timescales for the mi crowave and heating processes can be compared. Furthermore, a control mecha nism for ascertaining when to recompute the power distribution for use in t he thermal model will be postulated. It is found that this criterion depend s strongly on the changes that arise in the dielectric properties of the ma terial. Finally, the developed numerical algorithms are validated using a c omplicated industrial applicator design where the solutions for the tempera ture distribution are compared directly with experimental results. (C) 2000 Elsevier Science Inc. All rights reserved.