Multi Precision Modeling Method Of Complex Model And Its Application For Electromagnetic Scattering Based On LOD5-FDTD Method

Due to the finite difference time domain(FDTD)method can be intuitive description of the calculated electromagnetic problems and easy to program while in electromagnetic calculation,it has become an important numerical method in the electromagnetic simulation field.However,along with the development of science and technology,the calculation efficiency and precision are required higher and higher.Due to the limitation of modeling model complexity,efficiency of the traditional FDTD method algorithm is serious impacted when applied in electromagnetic simulation in practical.Therefore,in order to improve the practical application scope of modeling,this paper studies a new multi-order precision FDTD modeling method for complex model based on several popular commercial modeling softwares.Firstly,this paper reviews and summarizes the research progress of finite element modeling,then introduces a new FDTD modeling method based on triangular facet mesh.This method uses the triangular facets generated by commercial modeling software as the transformation medium to generate FDTD grid modeling space,which solves the problem of multi-component complex material modeling,cavity problem,and let users choose the model space size freely.At the same time,this method will be combined with CAD visualization,the correctness of complex model modeling can be verified,and be combined with MIE series solution,the accuracy and practicality of modeling can be verified.The modeling algorithm is easy to use and can obtain a large number of models of electromagnetic scattering data,laid the foundation for future engineering practice.Then,this paper presents a multi precision modeling method by modifying the above modeling method.A normal size mesh(first-order precision grid)is divided into eight small grids(second-order precision grid)with only half of the length,which improves the accuracy and resolution of the model.For the common parts of the model,the first-order precision grid is used to reduce the memory consumption,and for the components of the small parts or special materials,the second-order precision grid is used to enhance the resolution of the model to show the details of the parts,then different precision components will be integrated stack,at last the output of the final multi-order precision modeling files will be achieved.According to the above idea,a second-order precision grid is divided into eight third-order precision grids,and finally multi-order precision modeling method will be realized.At last,combined with CAD visualization,verify the correctness of modeling.Finally,in order to apply the multi-order precision modeling method to the electromagnetic scattering calculation,a second-order electromagnetic scattering algorithm based on LOD5-FDTD method is studied.The concrete conversion method of the electromagnetic field under the second-order precision grid and the concrete iterative formula of the electromagnetic field component under the second-order precision are studied in detail.The accuracy of the algorithm is verified by the comparison of the metal sphere and the MIE series.The second-order accuracy algorithm can improve the accuracy of the electromagnetic scattering operation by selecting the second-order precision of the different parts of the complex model.