电导率连续变化大地电磁无网格法数值模拟

发布时间：2018-04-20 12:40

本文选题：连续变化 + 大地电磁　；参考：《湖南大学学报(自然科学版)》2017年08期

【摘要】：针对地下空间目标体多为电性参数连续变化且分布形态复杂等特点,结合无网格法物性参数加载方便、计算精度较高、自适应分析便利等优势,基于径向基函数构造了连续导电模型下的形函数,推导了等价线性方程组,进行了电导率连续变化的二维大地电磁数值模拟,给出了形状参数最优值.通过电导率连续变化的水平层状模型验证了算法的正确性,计算结果均方根相对误差不超过0.36%,精度优于有限元法.讨论了电导率连续变化的水平模型与均匀分块模型的电磁响应差异,对连续变化的地堑模型和不同倾斜角度下油藏注水模型进行了数值模拟.研究表明:连续变化模型和均匀分块模型差异明显,在实际反演解释中采用连续变化模型有利于提高反演的精度;TM模式的观测方式对于异常体的倾斜分布具有更好的分辨能力;无网格法避免了复杂的模型输入和网格的生成,更适合计算电性参数连续变化和复杂分布的异常体响应,将成为复杂电性和分布形态下电磁探测高精度数值模拟新方法.
[Abstract]:In view of the characteristics that the objects in underground space are continuously changing in electrical parameters and the distribution forms are complex, combined with the advantages of the meshless method, such as convenient loading of physical property parameters, high calculation accuracy and convenient adaptive analysis, etc. Based on the radial basis function, the shape function under the continuous conduction model is constructed, the equivalent linear equation system is derived, the two-dimensional magnetotelluric numerical simulation of the continuous change of conductivity is carried out, and the optimum value of the shape parameter is given. The correctness of the algorithm is verified by the horizontal layered model with continuous variation of conductivity. The relative error of RMS is less than 0.36 and the accuracy is better than that of the finite element method. The difference of electromagnetic response between horizontal model and uniform block model of continuous conductivity variation is discussed. The continuous variation of graben model and reservoir water injection model with different inclined angles are numerically simulated. The results show that there are significant differences between the continuous variation model and the uniform block model, and the use of the continuous variation model in the actual inversion interpretation is helpful to improve the accuracy of inversion and the observation method of TM model has better resolution ability for the tilt distribution of abnormal bodies. The meshless method avoids complicated model input and mesh generation, and is more suitable for calculating the continuous variation of electrical parameters and the abnormal volume response of complex distribution. It will become a new method for high precision numerical simulation of electromagnetic detection under complex electrical properties and distribution patterns.
【作者单位】：吉林大学仪器科学与电气工程学院;地球信息探测仪器教育部重点实验室;
【基金】：国家自然科学基金资助项目(41674109) 国家重大科研装备研制资助项目(ZDYZ2012-1-05)~~
【分类号】：P631.325

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