A COMBINED ELECTROMAGNETIC AND HEAT TRANSFER MODEL FOR HEATING OF FOODS IN MICROWAVE COMBINATION OVENS

摘要

The objective of the present research was to establish a combined electromagnetic and heat transfer model to predict the temperature distribution in food loads during microwave and forced air heating in a microwave combination oven. The microwave process was modelled using the finite difference time domain (FDTD) method to numerically solve Maxwell's equations in three dimensions, assuming the food properties to be constant. The power dissipated at each cell in the computational domain was subsequently calculated. Heat transfer was modelled using Fourier's equation for heat conduction with convec-tive boundary conditions. The conduction model was spatially discretised using finite elements. The power dissipation field was transferred to the finite element heat transfer code using interpolation modules to couple the models. Validation experiments were made for comparisons with predicted temperatures inside a model food load with brick-shaped geometry. Good qualitative agreement between predicted and measured temperature profiles was obtained.