An approach for simulating the microwave heating process with a slow- rotating sample and a fast-rotating mode stirrer

[Display omitted] •A multiphysics model for heating process with a slow- rotating heated sample and a fast-rotating mode stirrer is developed.•The calculation amount is reduced by transformation methods based on the symmetry of geometric structure.•The combined effect of mode stirrer and turntable on microwave heating is analyzed.•The effect of the distance between the mode stirrer and the heated material on the heating effect is analyzed. Moving elements have been widely used in microwave heating process, especially mode stirrers and turntables. However, the huge difference in speed of these two elements makes the simulation of this heating process difficult to achieve. In this work, the heating process is computed by a step-by-step algorithm based on implicit function and level set methods. In each time step, the slow- rotating heated sample is considered as static while the fast-rotating mode stirrer have rotated a certain angle. The heat source in this time step is obtained by averaging the dissipated powers with mode stirrer in different angles. Moreover, the calculation amount is reduced by transformation methods based on the symmetry of geometric structure. In addition, heating process with different time step lengths and numbers of mode stirrer angles have been computed to analyze the model sensitivity. Experiments are also carried out to validate the effectiveness of the proposed method. Simulated results are in accordance with experimental ones. The combined effect of mode stirrer and turntable on microwave heating is analyzed. This model can serve as an effective method to deal with the thermal analysis with unequal velocity moving elements during the microwave heating.