In the present part the results of numerical simulations of flow and transport in media made up from circular inclusions of conductivity K that are submerged in a matrix of conductivity K-0, subjected to uniform mean velocity, are presented. This is achieved for a few values of kappa=K/K-0 (0.01, 0.1 and 10) and of the volume fraction n (0.05, 0.1 and 0.2). The numerical simulations (NS) are compared with the analytical approximate models presented in Part 1: the composite elements (CEA), the effective medium (EMA), the dilute system (DSA) and the first-order in the logconductivity variance (FOA). The comparison is made for the longitudinal velocity variance and for the longitudinal macrodispersivity. This is carried out for n<0.2, for which the theoretical and simulation models represent the same structure of random and independent inclusions distribution. The main result is that transport is quite accurately modeled by the EMA and CEA for low kappa, for which alpha(L) is large, whereas in the case of kappa=10, the EMA matches the NS for n<0.1. The first-order approximation is quite far apart from the NS for the values of examined kappa.
Jankovic, I., Fiori, A., Dagan, G. (2003). Flow and transport through two-dimensional isotropic media of binary conductivity distribution. Part 2: NUMERICAL simulations and comparison with theoretical results RID A-2321-2010. STOCHASTIC ENVIRONMENTAL RESEARCH AND RISK ASSESSMENT, 17(6), 384-393 [10.1007/s00477-003-0167-z].
Flow and transport through two-dimensional isotropic media of binary conductivity distribution. Part 2: NUMERICAL simulations and comparison with theoretical results RID A-2321-2010
FIORI, ALDO;
2003-01-01
Abstract
In the present part the results of numerical simulations of flow and transport in media made up from circular inclusions of conductivity K that are submerged in a matrix of conductivity K-0, subjected to uniform mean velocity, are presented. This is achieved for a few values of kappa=K/K-0 (0.01, 0.1 and 10) and of the volume fraction n (0.05, 0.1 and 0.2). The numerical simulations (NS) are compared with the analytical approximate models presented in Part 1: the composite elements (CEA), the effective medium (EMA), the dilute system (DSA) and the first-order in the logconductivity variance (FOA). The comparison is made for the longitudinal velocity variance and for the longitudinal macrodispersivity. This is carried out for n<0.2, for which the theoretical and simulation models represent the same structure of random and independent inclusions distribution. The main result is that transport is quite accurately modeled by the EMA and CEA for low kappa, for which alpha(L) is large, whereas in the case of kappa=10, the EMA matches the NS for n<0.1. The first-order approximation is quite far apart from the NS for the values of examined kappa.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
