摘要:

AbstractThe leakage effect in porous fissured media has been considered in a general sense by introducing a new expression of the leakage term in this paper. The double porosity concept is employed and the related expressions are formulated using the upwind finite element approach. Considering the infinite extension of the problem domain, a mapped transient infinite element has been presented to simulate the far field of the infinite medium. Since the mass transfer function of the present mapped transient infinite element is dependent on both space and time variables, the mechanism of transient contaminant migration problems in infinite porous fractured media can be rigorously simulated because the property matrices of the element are evaluated at any time of interest. By comparing the current numerical results with the analytical ones, the accuracy, correctness and effectiveness of the present method have been established. Three different time discretization schemes were examined and it was found that either the central difference or the backward difference approximation is suitable for the upwind finite element simulation of transient contaminant migration problems.

ISSN:0363-9061    

DOI:10.1002/nag.1610180802

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractUsing the numerical model presented in the first paper of this research,1a parametric study has been carried out in this paper to investigate the effect of several important parameters on the transient contaminant transport in infinite porous fractured media. From the related numerical results, it has been demonstrated that: (1) transmissive coefficient between the porous block and the fissured network has a significant influence on the value of the concentration but has little effect on the speed of contaminant transport; (2) porosities in the porous block and fissured network have a significant influence on the maximum value of the concentration; (3) average linear velocity of flow has a significant influence on both the concentration distribution and speed of contaminant transport; (4) dispersion coefficient of the medium affects not only the shape of the concentration versus time curve but also the peak value of the concentration.

ISSN:0363-9061    

DOI:10.1002/nag.1610180803

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe presence of any leak in a waste repository is going to cause some concern since it may lead to the contamination of the surrounding soil and groundwater. This is an important problem which occurs and recurs, sometimes despite the precautions taken to minimize the possibility of development of any leak. The effects of contaminant leakage in general are not well understood. Thus it is the aim in this paper to develop some semi‐analytical solutions of leakage problems occurring in deeply buried cylindrical repositories. In the solution approach, a series of integral transforms is used to simplify the governing equations and solutions are found in the transform space before numerical inversions are applied to obtain the contaminant concentrations in real space and time. To illustrate the application of the technique, results of some leakage cases are presente

ISSN:0363-9061    

DOI:10.1002/nag.1610180804

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610180805

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610180801

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY