Physically Based Model for Extracting Dual‐Permeability Parameters Using Non‐Newtonian Fluids. Issue 1 (11th July 2019)

• Record Type: Journal Article
• Authors: Basset, Christelle N.; Abou Najm, Majdi R.; Ammar, Ashtarout; Stewart, Ryan D.; Hauswirth, Scott C.; Saad, Georges
• Is Part Of: Vadose zone journal. Volume 18:Issue 1(2019)
• Page Start: 1
• Page End: 13
• Publication Date: 2019-07-11
• Subjects: Soil science -- Periodicals; Zone of aeration -- Periodicals; Groundwater flow -- Periodicals; Groundwater flow; Zone of aeration; Periodicals; Electronic journals; 631.4
• DOI: 10.2136/vzj2018.09.0172
• Languages: English
• ISSNs: 1539-1663

Abstract

Abstract : Core Ideas: We present a cost‐effective and simple method for dual‐permeability model parameterization. Physical characterization is done with only experimental results of saturated flow experiments. Model inputs require only saturated flow results with water and a non‐Newtonian fluid. Dual‐permeability models simulate flow and transport within soils characterized by preferential (macro) and matrix (micro) pore domains, with each exhibiting distinct hydraulic properties. The lack of suitable methods for determining appropriate and physically based model parameters remains a major challenge to applying these models. Here, we present a method that characterizes dual‐permeability model parameters using experimental results of saturated flows from water and a non‐Newtonian fluid. We present two submodels that solve for the effective pore sizes of micropores and macropores, with macropores represented either with cylindrical (for biological pores) or planar (for shrinkage cracks and fissures) pore geometries. The model also determines the percentage contribution ( w i ) of the representative macro‐ and micropores to water flow. We applied the model to experimental soil samples complemented with capillary tubes simulating the macropores and showed its ability to derive the bimodal pore size distributions in dual‐domain soils using only two fluids. As such, we present this method of characterization of dual structures for improved modeling of nonuniform preferential flow and transport in macroporous soils.