Improvement of the process of installing antennas on aircraft by domain decomposition methods

In this paper, we describe a domain decomposition method based on boundary element method, finite element method and high frequency techniques applied to the analysis of antenna performances mounted on aerostructures. The benefits of the sub-domain method are mainly the ability to deal with collaborative studies involving several companies and the reduction of the computation by one or more orders of magnitude especially in the context of parametric studies. Global type functions defined on fictitious surfaces surrounding radiating elements are proposed in this paper to deal with the computation of communication antenna far field patterns in a multi-domain way. By masking the complexity of the antenna (wires, thin surfaces, materials) the external domain of the aircraft can be closed allowing the use of CFIE integral equation better conditioned than EFIE and guaranteeing a much faster convergence, or asymptotic GO/PO/PTD techniques. The accuracy and efficiency of this technique is assessed by Directivity computations of communication VHF monopole antennas mounted on a Fokker 100 scaled mock-up. Domain decomposition results obtained by combining two sets of sub-domains are compared with direct boundary element methods and measurements.