用于地震波场模拟的变网格边长声格固体模型

PHONONIC LATTICE SOLID WITH VARIOUS GRID LENGTH FOR MODELING SEISMIC WAVES

提出一种新的用于地震波场模拟的变网格边长声格固体模型（Phononiclatticesolidwithvariousgridlength，简称PLSVL模型）．该模型通过改变不同介质中网格的边长来体现介质速度的变化，粒子在所有网格中的运动均保持每一步运行一个网格边长．详细推导了该模型的Boltzmann方程，证明该方程及其散射项的表达式与PLS模型相同，因而从该方程出发，可寻出宏观变量所满足的波动方程．新模型在同种网格内部的传输过程不存在误差，在界面产生的误差不会随时间而积累．本文同时给出了一个理论模型的波场模拟结果．

In this paper, we present a new cellular automata model for modeling seismic waves, the PLSVL model (Phononic lattice solid with vacuous grids length). In this model, we change the grid length according to the wave velocity, and the particles move one grid length at a bine step in all lattice grids. The lattice Boltzmann equation and its macroscopic limit for PLASVL are derived. At macroscopic limit the Boltzmann equation and its scattering term of PLSVL model is the same as of PLS model, and they have the same properties, so we can derive wave equation from the Boltzmann equation of PLSVL. There's no error in the transpoftation step inside one lattice grid; time increasing can not acctumulate the error generated at the interface. We also give a numerical example of the PLSVL model.