Computational modelling of variably saturated flow in porous media with complex three-dimensional geometries

• Published in: International journal for numerical methods in fluids Vol. 50; no. 9; pp. 1085 - 1117
• Main Authors: McBride, D., Cross, M., Croft, N., Bennett, C., Gebhardt, J.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 30-03-2006; Wiley
• Subjects: Computation; Computational fluid dynamics; Computational methods in fluid dynamics; Exact sciences and technology; Flows through porous media; Fluid dynamics; Fluid flow; Fundamental areas of phenomenology (including applications); heap leaching; heterogeneous media; Mathematical analysis; Mathematical models; Modelling; Nonhomogeneous flows; percolation flow; Physics; Porous media; saturated-unsaturated flow; Three dimensional; saturated-unsaturated flow; Computational fluid dynamics; Digital simulation; Water flow; Heap leaching; Finite volume methods; Computation time; Unsaturated porous medium; heterogeneous media; Porous medium flow; Three dimensional flow; Percolation; Modelling; percolation flow; Mesh generation
• ISSN: 0271-2091; 1097-0363
• DOI: 10.1002/fld.1087

A computational procedure is presented for solving complex variably saturated flows in porous media, that may easily be implemented into existing conventional finite‐volume‐based computational fluid dynamics codes, so that their functionality might be geared upon to readily enable the modelling of a complex suite of interacting fluid, thermal and chemical reaction process physics. This procedure has been integrated within a multi‐physics finite volume unstructured mesh framework, allowing arbitrarily complex three‐dimensional geometries to be modelled. The model is particularly targeted at ore heap‐leaching processes, which encounter complex flow problems, such as infiltration into dry soil, drainage, perched water tables and flow through heterogeneous materials, but is equally applicable to any process involving flow through porous media, such as in environmental recovery processes. The computational procedure is based on the mixed form of the classical Richards equation, employing an adaptive transformed mixed algorithm that is numerically robust and significantly reduces compute (or CPU) time. The computational procedure is accurate (compares well with other methods and analytical data), comprehensive (representing any kind of porous flow model), and is computationally efficient. As such, this procedure provides a suitable basis for the implementation of large‐scale industrial heap‐leach models. Copyright © 2005 John Wiley & Sons, Ltd.