TY - JOUR
T1 - Dispersion and connectivity in flow through fractured networks
AU - Lee, Cheng Haw
AU - Lin, Bih Shan
AU - Yu, Jim Li
N1 - Funding Information:
The authors are grateful to the National Science Council (NSC) and Radwaste Atomic Administration (RWA) in Taiwan for providing partial financial support for this study.
PY - 1994/6
Y1 - 1994/6
N2 - A stochastic modeling technique in a 2-D discrete fracture network with two orthogonal sets of fractures has been developed to observe mass transport dispersion, and to investigate the scaling law related to the mean square displacement of particle travel time, with various percolation probabilities. A law with a fractal dimension for dispersion in the discrete fracture network is estimated by analyzing the random walk with percolation theory, and by using the particle tracking method. Emphasis is placed on understanding how fracture connectivity influences dispersion in flows through fractured networks. Simulation results show that the distribution of masses is skewed or multimodal due to the low interconnection of fractures, and has an approximately Gaussian distribution at the high level of interconnection. Dispersion in fractured media is affected by the connectivity of fractures. Based on percolation theory analysis, numerical results show that there exists a threshold for fracture interconnectivity when the percolation factor is increased. In the case near the percolation threshold, a ratio exists between the mean square displacement of travel paths and time raised to the power value of 1.23, which agrees with the theoretic value of 1.27. Above the percolation threshold, an increasing percolation probability increases the slope of the scaling relationship between Ln vs. Ln in our study cases. An increasing connectivity of fractures decreases the variation of standard deviation in dispersion.
AB - A stochastic modeling technique in a 2-D discrete fracture network with two orthogonal sets of fractures has been developed to observe mass transport dispersion, and to investigate the scaling law related to the mean square displacement of particle travel time, with various percolation probabilities. A law with a fractal dimension for dispersion in the discrete fracture network is estimated by analyzing the random walk with percolation theory, and by using the particle tracking method. Emphasis is placed on understanding how fracture connectivity influences dispersion in flows through fractured networks. Simulation results show that the distribution of masses is skewed or multimodal due to the low interconnection of fractures, and has an approximately Gaussian distribution at the high level of interconnection. Dispersion in fractured media is affected by the connectivity of fractures. Based on percolation theory analysis, numerical results show that there exists a threshold for fracture interconnectivity when the percolation factor is increased. In the case near the percolation threshold, a ratio exists between the mean square displacement of travel paths and time raised to the power value of 1.23, which agrees with the theoretic value of 1.27. Above the percolation threshold, an increasing percolation probability increases the slope of the scaling relationship between Ln vs. Ln in our study cases. An increasing connectivity of fractures decreases the variation of standard deviation in dispersion.
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U2 - 10.1080/02533839.1994.9677618
DO - 10.1080/02533839.1994.9677618
M3 - Article
AN - SCOPUS:0028468719
SN - 0253-3839
VL - 17
SP - 521
EP - 535
JO - Journal of the Chinese Institute of Engineers, Transactions of the Chinese Institute of Engineers,Series A/Chung-kuo Kung Ch'eng Hsuch K'an
JF - Journal of the Chinese Institute of Engineers, Transactions of the Chinese Institute of Engineers,Series A/Chung-kuo Kung Ch'eng Hsuch K'an
IS - 4
ER -