New thin wire formulation for time‐domain differential‐equation models

A novel thin wire formulation for the description of thin wires in coarse numerical models is described. This new approach uses the exact local field expansions around the thin wire which are mapped onto the coarse mesh. The method is accurate, overcomes existing limitations and approximations, does not incur additional computational overheads, requires no empirical factors, and can be extended to other fine feature objects. In this paper, the complete derivation is presented with numerical results and examples used for validation. Further significant extensions of the work is described as a separate section to emphasize possibilities and generality of the method.