Seismic wavefield numerical simulation by temporal high-order finite difference method based on rectangular/cuboid grid elements
The finite difference(FD)method is widely used to solve different types of seismic wave equations.It's crucial to simultaneously improve the FD accuracy for seismic wavefield simulation in the temporal domain and the spatial domain.To promote the accuracy and flexibility of the existing high-order FD method in the spatio-tempral domain,this paper proposes an improved spatio-tempral high-order FD method based on rectangular/cuboid grid elements and solves the 2D and 3D acoustic equations,respectively.The improved FD method com-bines off-axis grid nodes and traditional axial nodes to jointly approximate partial derivatives and further applies plane wave theory and Taylor series expansion method to compute the high-order FD coefficients of the improved stencils.Numerical accuracy analysis indicates that the improved FD method presents higher numerical accuracy and stability than the traditional one.Several computational examples by models demonstrate that under the identi-cal conditions of model parameters,the proposed FD method can generate higher temporal-domain simulation ac-curacy while keeping satisfactory spatial-domain simulation accuracy.In addition,the improved stencil can adopt different grid spacing along different spatial directions,which effectively increases the flexibility of wavefield simu-lation and can provide an effective wavefield extrapolation tool for seismic imaging and inversion.
万方数据
维普
