Numerical modeling of microwave induced natural convection

A three-dimensional numerical model is developed to predict the distribution of electromagnetic fields, power distributions, temperatures, and velocities within a containerized liquid located in a microwave cavity. A three-dimensional Finite-Difference-Time-Domain (FDTD) scheme is used to determine electromagnetic fields and absorbed power by solving the transient Maxwell’s equations, and the Finite Control Volume method with SIMPLER algorithm is used to obtain unsteady temperature profiles and flow patterns. Temperature dependence of liquid dielectric properties is simulated through an iterative process. Two liquids, distilled water and corn oil, are chosen to illustrate microwave heating phenomena for high and low loss dielectrics, respectively.