Evaluation of movement discretization over rotating stirrers in microwave ovens

Problems involving stirrers or sample movement are common in many industrial applications for microwave heating processes using multimode applicators to obtain a uniform electric field absorption in the material. The electromagnetic field is enforced to change its spatial pattern with time over the sample. The electromagnetic field when evaluating a sample that moves or under the influence or moving stirrers within a microwave oven is usually simulated obtaining the desired results of the discretizated positions of the movements. In this work the influence of the discretization of the movement of the stirrers is evaluated attending to different loading materials and cavity sizes by studying the obtained electric field results. A criterion based in meshing procedures is evaluated for this kind of problems where rotating stirrers or moving samples may appear. With this purpose the relative error for the electric field using different discretization angles is obtained using the solution for the finest step. The evaluated criterion may be very useful when dealing with this kind of problems to ensure a required minimum accuracy.