直流电阻率2.5维有限元数值模拟

2.5-D direct current resistivity modelling by finite-element method

从稳定电流场满足的基本微分方程出发,推导了地面点源电场电位边值问题对应的等价变分问题.用网格离散积分区域时,以四边形为最小研究单元.针对电场在电源附近衰减快,变化梯度大,数值模拟结果在电源附近位置有较大误差问题,采用边界/奇异校正算法改善模拟结果在电源附近的奇异性问题,同时减少边界条件的影响,提高模拟结果精度.从波数域电位求取空间域电位,利用最优化离散波数进行反付氏变换.模型算例结果验证了该算法的可行性与有效性.

Based on the governing equation of stable electrical current flow field, we obtain the variational equations corresponding to boundary value problems.The integral area is discretized into rectangle elements.With respect to problem of electrical potential falls off rapidly near a source,we apply correction for boundary conditions and the source singularities to improve the accuracy of the simulated results.Optimization wavenumber is used to solve inverse Fourier-cosine transformation.The example model case demonstrate the feasibility and efficiency of the forward routine.