Simulation Seismic Wave Propagation in Topographic Structures Using Asymmetric Staggered Grids
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摘要: 提出了一种新的三维空间对称交错网格差分方法,模拟地形构造中弹性波传播过程.通过具有二阶时间精度和四阶空间精度的不规则网格差分算子用来近似一阶弹性波动方程,引入附加差分公式解决非均匀交错网格的不对称问题.该方法无需在精细网格和粗糙网格间进行插值,所有网格点上的计算在同一次空间迭代中完成.使用精细不规则网格处理海底粗糙界面、 断层和空间界面等复杂几何构造, 理论分析和数值算例表明, 该方法不但节省了大量内存和计算时间, 而且具有令人满意的稳定性和精度.在模拟地形构造中地震波传播时,该方法比常规方法效率更高.Abstract: A new 3D finite-difference(FD)method of spatially asymmetric staggered grids was presented to simulate elastic wave pro pagation in to pographic structures.The method approximated the first-order elastic wave equations by irregular grids finite difference operator with second-order time precise and fourth-order spatial precise.Additional intro duced finite difference formula solved the asymmetric problem arisen in non-uniform staggered grid scheme.The method had nointer polation between the fine and coarse grids.All grids were computed at the same spatial iteration.Complicated geometrical structures like rough submarine inter face,fault and nonplanar inter faces were treated with fine irregular grids.Theor etical analysis and numerical simulations show that this method saves consider able memory and computing time,at the same time,has satisfactory stability and accuracy.
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Key words:
- finite difference /
- asymmetric staggered grid /
- seismic wave
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