Of Mei Equation Morbid Study

MEI is an effective numerical method to truncate finite difference mesh. It has two advantages: first, allowing the grid to be truncated very close to scatter surface; second, obtaining a sparse matrix. Because of these two advantages, MEI Method has attracted many researcher's interesting since it was put forward by professor K.K.MEI in 1992, and it has been applied in many fields.Following works has been done in this paper:First, classical MEI Method has been studied. MEI theory is analyzed, related formulas are deduced and a Fortran language computer program is coded. By this program, some scattering problems are solved. The induced currents are calculated. To check the validity of these numerical results, related MoM (Method of Moment) solutions are also given out.Second, the ill-conditioning of the MEI equation has been studied. The condition number of MEI equation has been studied in detail for the first time. And a Fortran language computer program is developed to get the condition number. By this program, condition numbers of some 2D conducting cylinder are calculated. The numerical results show that condition numbers for circular cases are much more larger than that of rectangular cases. This indicates that the MEI for 2D circular conducting cylinder is much more ill than that of rectangular case. This conclusion is very useful in engineering application.The results by Fortran language computer program are checked by that of MATLAB.Third, scattering by 2D circular conducting cylinder is put under studied, due to that its MEI is much more ill than other case. Many calculations have been done for different radius cases. By summarizing these results, we get two conclusions: (1) the MEI solutions will no longer be accurate with cylinder radius going bigger if the calculating parameters keep the same; (2) the number of metron and integral step-size has great impact on computation results, independently.Ways to improve the MEI results have been carried out. Results of many scattering...