3-D discontinuous sheet for finite-element time-domain modelling of thin metallic films

A dual surface method is presented for the modelling of thin metallic film surfaces. Improved accuracy is achieved over existing single surface techniques by way of enforcing the field discontinuity across the thin film layer. The implementation of this discontinuous sheet in the wave equation is described for the time-domain finite-element method based on the use of edge elements. Validation of the numerical implementation is provided by comparison of the thin film performance, due to variations in film thickness and conductivity, with analytical expressions and experimental results. A typical application of thin metallic films in food active packaging is analysed for a multicomponent food package placed within a multimode microwave heating applicator.