Research On Discontinuous Galerkin Time-domain Finite Element P-adaptive Electromagnetic Analysis Technology

In recent decades,the finite-element time-domain(FETD)method has received much attention of the researchers in the field of computational electromagnetics.It can not only model complex geometry structures and inhomogeneous materials,but also obtain the broadband characterization of object.Nonetheless,a large system of equations needs to be inverted at each time step in the conventional FETD,resulting in a heavy computational cost.To overcome this drawback,the discontinuous Galerkin method is one of effective techniques.The discontinuous Galerkin finite element time domain method(DG-FETD)method is a special kind of finite element method combined with the discontinuous Galerkin method,which can obtain a block diagonal mass matrix and has natural parallelizability.In the paper,DG-FETD method is applied to analyze the electromagnetic scattering.The discontinuous Galerkin finite element time domain method(DG-FETD)method,allows the two sides of the interface to interpolate the field values of the respective elements by using the basis functions of different orders.In the coarser grid,high order basis functions are used in areas where refinement is needed,while the rest are of low order.This ensures the accuracy while reducing the number of unknown quantities.In addition,the mixed basis functions of different high-low order are realized,which can speed up computation efficiently without being affected by the minimum partition size.For dispersion medium that often appears in actual engineering problems,whose dielectric parameter changes with frequency,this dissertation introduces three kinds of commonly used frequency domain models.Taking the example of Debye model,this dissertation also deduce multipole Debye model calculation formula using p-adaptive DG-FETD and verify the accuracy of algorithm by numerical examples.