A Hybrid ALE/Implicit Function Method for Simulating Microwave Heating with Rotating Objects of Arbitrary Shape

Abstract Moving objects are widely applied in microwave heating process for improving heating uniformity. In order to improve the heating effect, various moving objects with complex shapes will be used in microwave heating. However, for objects with irregular shapes, it is difficult to model the object movement due to the difficulty of characterizing the object’s boundaries. In this paper, by using Arbitrary Lagrange Eulerian (ALE) method to track the object movement, the position of the object is expressed by a time-varying implicit function. The impact of the moving object on the electromagnetic field distribution is therefore represented by the change of the implicit parameter. Meanwhile, after the heat source is transformed back to the initial position by a coordinate transformation method, the calculation of the heating process of the moving object can be realized in a fixed mesh structure, thus re-meshing is avoided. A 2-D model and a 3-D model with rotating objects in irregular shapes are used to illustrate the proposed method. Experiments are conducted to testify the validity of the proposed method. Good agreements have been obtained. Moreover, the results show that, for dealing with the cases with moving objects in complex shapes, this method is much more accurate and efficient than the ALE-remeshing method.