关键词: 细观渗流, 孔隙介质, DLA模型, 实验

Abstract: Many engineering problems are closely related to the shape of seepage.The classical seepage mechanics can not be used to investigate the effect of meso structure of porous media on the shape of seepage because it is based on the assumption of homogenous media.Based on the meso seepage experiment in sandstone,the effect of the meso structure of porous media on the shape of seepage boundary is investigated in the paper.And the DLA effect of evolution of seepage boundary is analyzed.The relationship between the seepage of uncompressible fluid described by the Darcy' s Law and the Laplacian fractals is suggested theoretically.Moreover,the stochastic differential equation of seepage boundary is proposed and the mechanism of seepage evolution is analyzed.The stochastic approach is initially proved by the agreement of theoretical value with the experimental results.It is indicated that the complexity of seepage boundary is caused by the mutual influence of the average motion described by the Darcy' s Law and the fluctuation factor determined by the meso structure of porous media.The reason for the DLA effect of seepage boundary is the inhomogenous spatial distribution of pores in porous media.The conclusion of the paper can also be used to analyze the viscous fingering phenomenon in the process of oil displacing by water.

Key words: seepage at the meso scale, porous media, DLA model, experiment