改进BISQ模型的双相介质地震波场数值模拟及频散校正

从改进BlSQ模型的双相介质所对应的速度-应力运动方程出发,构建2×2N阶交错网格有限差分模拟算法:同时,为压制模拟过程中的数值频散现象,采用通量校正传输(FCT)技术获得带FCT修正的交错网格有限差分模拟算法,对各向同性双相介质进行地震波场数值模拟.研究结果表明:(1)波场存在快纵波、慢纵波和横波等波场特征,并与模型的理论响应相符,说明交错网格模拟算法具有正确性和可行性；(2)采用FCT修正的交错网模拟算法能够有效压制数值频散,并保留真实的波场特征.

Seismic modeling and numerical dispersion correcting in double-phase medium based on reformulated BISQ model

Based on first-order velocity?stress equations of reformulated BISQ theory in double-phase media,the simulation algorithm of the finite difference of 2-order time and 2N-order space staggered grids was constructed.Meanwhile,in order to suppress the numerical dispersion phenomenon during the process of the simulation,the flux-corrected transport(FCT) technique was discussed,and the algorithm of the finite difference of staggered grids was obtained,in which the FCT correcting was assembled.The algorithm was validated by simulating the wave-fields in isotropic double-phase media.The results show that: firstly,the existence of fast compressional wave,slow compressional wave and shear wave in wave-fields accords with the response of the model,which shows that the simulation algorithm of staggered grids is valid and practical.Secondly,with the use of algorithm of staggered grids which is corrected by FCT,dispersion can be effectively suppressed and the real wave-fields oscillation can be retained as well.