球面电磁波斜入射建筑物内场的数值分析

Numerical analysis of time-domain response for building under oblique incidence of spherical electromagnetic wave

为了分析窄带电磁脉冲源近、远场辐照大型建筑物内部空间电磁场分布特点,采用时域有限差分方法,对比分析平面波、球面波场源正面斜入射多层多单元建筑物的计算结果,并较为全面地分析了各房间各水平面中心电场强度幅值、各层各水平面电场强度最大值分布情况。建筑物各层相对应高度面上场强分布近似,在电磁波传播方向上窗户房间内部区域场强较强,两种波场源入射结果基本一致;在其余区域场强较弱,特别是在较大空间内的区域,球面波场源入射下场强相对更弱。其中通过与待模拟建筑物外形相紧凑性匹配的球面波场源构建,模拟仿真了窄带球面电磁波在真空空间的辐射传播,计算结果验证所构建球面波近场源准确可行。

To understand distribution characteristics of electromagnetic field in the building under near-and far-field radiation by narrow band electromagnetic pulse,computation results of multiple-storey multi-unit building under oblique incidence of plane and spherical electromagnetic waves are comparatively analyzed by finite-difference time-domain（FDTD）method.The electrical field amplitude at centers of different altitude planes in room and the maximum distribution of electrical field strength at different altitude planes in building are generally analyzed.The field distribution of corresponding altitude planes on each floor in building is similar.The field strength of areas where the incident wave propagates from windows into rooms is stronger,and is identical under the incidence of both kinds of electromagnetic waves.The field strength of the rest areas in wider space under incidence of spherical wave is weaker than that under incidence of plane wave.By used of the field source with spherical electromagnetic wave closely fitting the building form,the spherical wave of narrow band propagating in empty space is simulated,and computation results prove the field source of spherical wave constructed accurately workable.