Calculation method of fvfd far-field integral boundary condition with reduced grid usage

Abstract

The present invention provides a FVFD far-field integral boundary condition calculation method that reduces grid usage, establishes a simulation model, and circulates the virtual time step of the simulation model until the end of convergence; in each virtual time sub-iteration process, each The space flux calculation and the implicit iterative solution calculation are performed on the mesh grid and each grid unit, and the next-level virtual time sub-iteration steps are updated to conserve the electromagnetic field value. The MUSCL format interpolation is used to calculate the state variables at the corresponding boundaries inside the area, and the equivalent current and magnetic current calculated at the internal virtual integral surface are used to calculate the external flow state variables. The invention reduces the Fourier transform link required for calculating the electromagnetic characteristics of the target in the time domain, and avoids a large number of convolution calculation problems encountered in the calculation of the boundary conditions of the same type of time domain integral equation.

Description

technical field [0001] The present invention relates to the technical field of numerical solution in the frequency domain of electromagnetics, in particular to a calculation method for FVFD (Finite Volume Frequency Domain, FVFD) far-field integral boundary conditions that reduces grid usage. Background technique [0002] With the complexity of electromagnetic scattering of complex-shaped targets in engineering, electromagnetic interference in complex electromagnetic environments, and the improvement of computer storage and computing capabilities, numerical calculation of electromagnetic fields has become possible. Time-domain calculations are beneficial for simulating radiation and scattering of broadband pulsed electromagnetic signals, among which Finite Difference Time Domain (FDTD) and Finite Volume Time Domain (FVTD) are the most famous methods, but if the incident wave is Single-frequency harmonic signals can be calculated in the frequency domain. Traditional frequency...

AI Technical Summary

Problems solved by technology

[0003] The calculation of electromagnetic fields by the micro-classification method is an open-field calculation problem. The larger the physical calculation space is, the greater the storage and calculation requirements are, so the calculation space must be truncated and boundary conditions must be set at the boundary. The function is to make the limited calculation space Equivalent to infinite space, let the electromagnetic wave traveling to the boundary have no obvious non-physical electromagnetic wave reflection, otherwise the internal field will be distorted and the numerical calculation accuracy will be seriously affected

However, the currently used unidirectional wave interpolation absorption boundary and zero-incident electromagnetic flux compatibility conditions are difficult and complex to apply, and there are requirements for the shape of the external boundary, and because the far-field boundary of the large reflection clutter needs to be far away from the electromagnetic field area of ​​interest, it is difficult to Due to the increase of the amount of grids and calculation burden, in view of the unique advantages and engineering requirements of the field calculation micro-classification method in simulating complex detailed structures and non-uniform materials, it is urgent to reduce the calculation grid area and improve calculation efficiency. Far-field truncation boundary condition processing algorithm

Images