摘要
在粗网格内先统计渗透率在粗网格中的概率分布 ,利用Dagan渗透率粗化积分方程通过渗透率概率分布计算粗化网格的等效渗透率 ,并由等效渗透率计算了粗化网格的压强分布 ,计算压强时还将渗透率自适应网格技术应用于三维渗流方程的网格粗化算法中 ,在渗透率或孔隙度变化异常区域自动采用精细网格 ,用直接解法求解渗透率或孔隙度变化异常区域的压强分布。整个求解区采用不均匀网格粗化 ,在流体流速高的区域采用精细网格。利用本文方法计算了三维渗流方程的压强分布 ,结果表明这种算法的解在渗透率或孔隙度异常区的压强分布规律非常逼近精细网格的解 ,在其他区域压强分布规律非常逼近粗化算法的解 ,计算速度比采用精细网格提高了约 10 0倍。
In the coarsen grid blocks, firstly, the probability density function of permeability by statistical method is computed, then using Dagan's integration equation the effective permeability by the probability density function of permeability is computed, the pressure distribution has been calculated by the effective permeability in all coarsen grid blocks. In the paper, the adaptive grid technology has been applied to upscaling method of 3D fluid equations in porous media. The fine grid blocks have been automatically adopted and the 3D fluid equations in porous media have also been solved by direct method where permeability or porosity change is abnormity. In the other region the nonuniform upscaling method has been adopted, i.e. using fine grid blocks in the high flow regions of the model. Using the method we have calculated the pressure distribution of the 3D fluid equations in porous media. The results show that the solutions of adaptive nonuniform upscaling method of 3D fluid equations in porous media are very approaching that of adopting fine grid blocks in the regions where the permeability or porosity change is abnormity and very approaching that of adopting coarsen grid blocks in the other region, however, the computing speed of adaptive upscaling method is 100 times faster than that of fine grid block method.
出处
《应用力学学报》
CAS
CSCD
北大核心
2003年第3期15-20,共6页
Chinese Journal of Applied Mechanics
基金
国家"973"项目G19990 43 3 11资助
