Coupled electromagnetic and termal modeling of microwave oven heating of foods

Temperature distributions from heating in a domestic microwave oven were st udied by considering the coupling between the electromagnetics and heat tra nsfer through changes in dielectric properties during heating. Maxwell's eq uations for electromagnetics and the thermal energy equations are solved nu merically using two separate finite-element softwares. The coupling between the softwares was developed by writing special modules that interfaced the se softwares at the system level. Experimentally measured temperature profi les were compared with the numerical predictions. The importance of couplin g was evident when the properties changed significantly with temperature fo r low and high dielectric loss materials and more so for the high loss mate rials. For moderate loss materials, when the properties do not change as mu ch with temperature, coupled solutions lead to results very close to the re sults for the uncoupled solution.