【摘要】 本文利用交错网格、辅助网格、旋转交错网格、同位网格有限差分方法分别模拟了二维弹性TTI介质和二维黏弹性TTI介质中的地震波传播.在稳定性条件内,选用不同的网格间距及时间间隔,通过波场快照、合成理论地震图较为系统分析对比了这四种不同网格有限差分数值模拟在计算精度、CPU时间、相移、频散、以及保幅方面的优缺点.数值模拟结果表明:1)这四种不同网格有限差分算法都是很好的波场数值模拟算法;2)就CPU计算时间而言,旋转交错网格有限差分算法的计算效率最高;3)从计算精度来看,同位网格有限差分的计算精度最高;4)从振幅保护方面来看,四种网格的保护振幅的能力相当;5)相移方面,当网格间距增大时,交错网格和旋转交错网格有可能出现相移现象;6)频散方面,同位网格的频散现象不明显.更多还原

【Abstract】 In this paper,we use the staggered grid,auxiliary grid,rotated staggered grid and non-staggered grid finite difference methods to simulate the wavefield in 2D elastic and viscoelastic TTI media,respectively.Under the stability criterion,we choose different spatial and temporal intervals to get snapshots and synthetic seismogram to compare the four algorithms in terms of accuracy,CPU time,phase shift,dispersion and amplitude protection.The numerical results show that: 1) all of the four finite difference algorithms are suitable for seismic wavefield simulation;2) the rotated staggered grid has the fastest CPU time;3) the non-staggered grid has the highest accuracy;4) the abilities of the four girds to protect the amplitude are nearly the same;5) the staggered grid and rotated staggered gird may appear phase shift when the spatial interval becomes larger;6) the non-staggered grid has a low dispersion phenomenon.更多还原