Finite Element Analysis Of Three-dimensional Electromagnetic Scattering. Non-uniform Media And Their Hybrid Methods: Theory And Applications

In electromagnetics, electromagnetic scattering in inhomogeneous media has became hot spot. However, because of the complex structure of media and the complex boundary conditions, These problems bring along the difficulty of the research. Traditional analysis approach is unable to solve these problems, so numerical techni-que is the better choice of solution; But using the Method of Moment (MoM) always results in complex Green's function, sometimes which even can't be got. The Finite Element Method (FEM), as a good choice of solving these problems, can solve all kinds of problem with inhomogeneous media, complex boundary conditions and complex source conditions. In this paper, FEM is studied as the solution of these problems. In this paper, emphasis is put on the investigation of induced well-logging by FEM. In these problems, special receiving-transmitting coils has been introduced in order to banishing directly coupling signal, such as orthogonal receiving-transmitting coils, orthogonal double-receiving coils. And the logging response is simulated by using FEM. Then the simulation results are compared to the one excited by ordinary coils so as to study the improving extent after using these coils. In electrical logging ,for the fixation of coils, coils could sometimes be put into special mandrel, at the same time, logging response is simulated so as to inspect the influence on the response. Finally, for some reasons, deviated well is sometimes drilled. The simulated result is given. Simultaneously, results by some dip angle is compared. Also, in this paper, some truncated conditions, which are used to truncate the solving region in FEM in order to decrease the unknown, are introduced such as Absorbing boundary conditions(ABC), perfectly matched layer(PML) and Finite Element-Boun-dary Integral Methods(FEM-BI). FEM is elaborately described, which include the variational formulation, vector basis function and ABC.PML which can be used in FEM. And it is described how to derive anisotropic PML absorbing by Maxwell's equations in a stretched coordinate system. Then, FEM-BI is introduced in detail, include the derivation of boundary integral formulation and. finite element formulati-on, the solution of singularity of boundary integral, and the comparison and discussion of the solution of the FEM-BI system. Based on the fact that FEM always can lead to special sparse systems, a new storage s –cheme, which can be called row-indexed sparse storage mode, is introduced, so the...