CAJ | 학술논문

针对矩形大定源介绍了一种层状导电模型瞬变电磁响应的快速计算方法.其基本思想是,将大定源回线源用较少的有限大小方形回线叠加.在频率域,该叠加过程导出矩形大定源回线模型响应可以表示为一个标准的Hankel积分,叠加效应仅仅是相应Bessel函数的空间积分过程.瞬变电磁响应可以利用余弦变换由频率域响应获得.均匀半空间模型计算结果和解析解较为吻合,层状模型模拟结果符合物理规律,不同测点位置感应电动势的视电阻率具有很好的一致性.新方法误差只是来源于圆回线对小方形回线的等效误差.与均匀半空间解析结果比较,只用16个方形回线等效,相对误差就可以小于10~(-3).
침대구형대정원개소료일충층상도전모형순변전자향응적쾌속계산방법.기기본사상시,장대정원회선원용교소적유한대소방형회선첩가.재빈솔역,해첩가과정도출구형대정원회선모형향응가이표시위일개표준적Hankel적분,첩가효응부부시상응Bessel함수적공간적분과정.순변전자향응가이이용여현변환유빈솔역향응획득.균균반공간모형계산결과화해석해교위문합,층상모형모의결과부합물리규률,불동측점위치감응전동세적시전조솔구유흔호적일치성.신방법오차지시래원우원회선대소방형회선적등효오차.여균균반공간해석결과비교,지용16개방형회선등효,상대오차취가이소우10~(-3).
The paper introduces a new method for computing the transient electromagnetic (TEM) response from a large rectangular loop over a layered earth. In the method, the large loop is spanned by fictitious squares. The response from each square are then summed up as that of the large loop. In frequency domain, the superposition leads the vertical magnetic field to be expressed as a standard Hankel integral, whose integrand contains the addition of 0-order Bessel functions involving the distance from the center of each square to calculating point. Time-domain response can then be cosine transformed directly from the frequency domain result. The error of the method stems from the approximation of square loop by circular one, and comparing with analytical response of half space, relative error is less than 10~(-3) with only 16 squares used.