Methodologies for electromagnetic field modeling for computer aided analysis of multi-domain physical interactions

multi-physics;multi-physics modeling;multi-timescale;electromagnetics;numerical electromagnetics;electromagnetic modeling;time domain method;finite difference time domain method;moving boundaries;curved boundaries;Lagrange method;Lagrangian method;Lagrangian mapping method;passive intermodulation;multi-time partial differential equation;multi-variate partial differential equation

Russer, Johannes A.

关键词: multi-physics;    multi-physics modeling;    multi-timescale;    electromagnetics;    numerical electromagnetics;    electromagnetic modeling;    time domain method;    finite difference time domain method;    moving boundaries;    curved boundaries;    Lagrange method;    Lagrangian method;    Lagrangian mapping method;    passive intermodulation;    multi-time partial differential equation;    multi-variate partial differential equation;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/15578/Russer_Johannes.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Several methodologies are presented in this work to facilitate the modeling of electromagnetic fields in the context of multi-domain physical interactions. Among the challenges for computer aided analysis of electromagnetic problems in interaction with other physical phenomena are the largely different temporal and spatial scales that may occur and the task of maintaining accuracy and computational efficiency in the implementation of boundary conditions for time-varying media.First, we present a methodology for the phenomenological modeling of passive intermodulation generation in metallic contacts due to electron tunneling. The methodology provides for the development of passive intermodulation source models that are compatible with general-purposeelectromagnetic and non-linear network analysis-oriented circuit simulators. The derived model allows for an investigation of theimpact of surface roughness and skin effect on the levels and frequency dependence of passive intermodulation interference. Thus, the model is intended to enhance the understanding of the passive intermodulation source due to electron tunneling in metallic contacts. The second methodology presented is a Lagrangian approach for increasing the accuracy of the finite difference time domain method for modeling wave propagation in geometries involving curved and moving boundaries. This methodology provides for the definition of an equivalent electromagnetic boundary value problem over a domain with fixed boundaries. A modified time-dependent operator is derived for the Lagrangian formulation, operating on a modified set of Maxwell's equationson a reference domain. This method relaxes spatial oversampling requirement and achieves high accuracy and computational efficiency.The third methodology provides for an efficient analysis of problems with widely separated time scales. We propose the application of the method of multi-time partial differential equations to the numerical solution of one-dimensional electromagnetic wave interactions involving highly disparate temporal variations in both excitation and time-varying media properties and boundary conditions. The temporal oversampling requirement is relaxed by introducing multiple time scales for quasi-periodic functions and, upon solution of the multivariate partial differential equation, we recover a solution to the univariate problem.