非均匀介质中交错网格高阶有限差分数值模拟

地震波场的数值模拟一直是地球物理学的一个重要的研究领域,而在数值正演模拟方法的研究中,计算精度和计算效率是评价该方法有效性及优越性的二个关键问题。这里从一阶速度—应力弹性波动方程出发,着重介绍如何构造离散化模型的网格,如何求解空间导数,如何选取边界条件等内容,从而更有效地提高数值计算的精度与计算效率。文中构造了不同类型的介质模型,并在交错网格中,利用高阶有限差分模拟非均匀介质的波场传播。模拟结果表明,该方法实现简单,具有很好地稳定性和较高的精度,能够直观、高效地反映出介质中波场的传播规律。

High-order difference modeling of heterogeneous media with staggered-grid

During the forward modeling,the computation precision and the efficiency are two pivotal questions to evaluate the validity and superiority of the method.Based on the one-order velocity-stress elastic wave equation,this paper emphasizes on improving the computation precision and the efficiency from to compartmentalize the discrete grid,solve the spacial derivative and add the boundary condition.The snapshots of the wave-filed of heterogeneous media using the high-order difference forward modeling with staggered-grid show the propagation law of the wave in different media more intuitively and effectively,and furthermore,validate that this method is easy and practical.