A finite element model for simulating temperature distributions in rotating food during microwave heating

With considering the continuous rotation of the turntable during microwave heating, a three-dimensional computer model based on FEM was successfully developed to predict time-dependent temperatures distributions of food sample. The slide interface between rotating and stationary part were specially assigned and treated, as the disconnections of the nodes occur during rotating which may cause the electromagnetic analysis result in error. On this basis, temperature was estimated by coupling electromagnetic and heat transfer analysis, whereas the node coordinate and dielectric properties of sample were updated with time steps, and the heat generations were renewed according to these parameters. To approximate the rotation and simulate the temperature, different methods were proposed and discussed in view of sample's shape and dielectric properties. These methods were then respectively optimized to achieve the minimum computational time and were experimentally validated by comparing with temperature distributions captured by an infrared thermal camera. (C) 2012 Elsevier Ltd. All rights reserved.