网格剖分及其精度和计算量分析

网格剖分程度直接影响着地震波正演数值模拟的计算精度及其计算量.以均匀介质模型为例,分析不同网格大小对波场模拟精度和计算量的影响,得出精细化网格剖分是实现高精度地震波正演模拟的有效方法,然而其计算量较大.以均匀倾斜介质模型为例,探讨倾斜地层网格剖分问题,数值实例分析不同震源频率对不同网格剖分方案引起的波场传播精度的影响,...

MESH GENERATION AND ITS ACCURACY AND COMPUTATIONAL AMOUNT ANALYSIS

Mesh Generation level can directly affect the accuracy and memory of seismic wave numerical simulation. The paper takes isotropie medium model as example to analyze the effect of different grid sizes on wave field simulating precision and calculated amount, and concludes that the fine grid can achieve the purpose of high-precision, but with disadvantage of calculated amount, then takes isotropic tilted medium model as another example to discuss the mesh generation problems on the tilted formation, uses numerical examples to analyze the wave field propagating effect of the different source frequency caused by different mesh generation strategy, and at the same time puts forward the rational mesh generation, and builds the approximating relationship between difference order and adjusted factor. The theoretical analysis and numerical experiments shows that the larger the grid step, the greater step effect induced by mesh generation of the tilted formation, under the condition of the grid size satisfying the rational dispersion relationship, selecting rational heterogametic mesh generation strategy can reduce the calculated amount, especially suppresses the bogus wave field raised by the mesh generation on the tilted formation, which ensures the numerical wave field with high S/N and credibility, and at the same time, points out that properly reducing the grid step and improving the difference order can improve the computational effect under the condition of ensuring the computational precision.