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  • Articles  (16)
  • porous media  (16)
  • 2010-2014
  • 2000-2004  (2)
  • 1990-1994  (12)
  • 1985-1989  (2)
  • 1950-1954
  • Technology  (16)
  • 1
    Electronic Resource
    Electronic Resource
    Effects of Precursor Wetting Films in Immiscible Displacement Through Porous Media (2000)
    Springer
    Transport in porous media 38 (2000), S. 291-317 
    Details
    ISSN: 1573-1634
    Keywords: wetting film ; pinch-off ; immiscible displacement ; two-phase flow ; porous media ; oil recovery ; soil remediation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Technology
    Notes: Abstract A computer-aided simulator of immiscible displacement in strongly water-wet consolidated porous media that takes into account the effects of the wetting films is developed. The porous medium is modeled as a three-dimensional network of randomly sized unit cells of the constricted-tube type. Precursor wetting films are assumed to advance through the microroughness of the pore walls. Two types of pore wall microroughness are considered. In the first type of microroughness, the film advances quickly, driven by capillary pressure. In the second type, the meniscus moves relatively slowly, driven by local bulk pressure differences. In the latter case, the wetting film often forms a collar that squeezes the thread of oil causing oil disconnection. Each pore is assumed to have either one of the aforementioned microroughness types, or both. The type of microroughness in each pore is assigned randomly. The simulator is used to predict the residual oil saturation as a function of the pertinent parameters (capillary number, viscosity ratio, fraction of pores with each type of wall microroughness). These results are compared with those obtained in the absence of wetting films. It is found that wetting films cause substantial increase of the residual oil saturation. Furthermore, the action of the wetting films causes an increase of the mean volume of the residual oil ganglia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006557114996
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  • 2
    Electronic Resource
    Electronic Resource
    Macroscale Thermodynamics and the Chemical Potential for Swelling Porous Media (2000)
    Springer
    Transport in porous media 39 (2000), S. 187-225 
    Details
    ISSN: 1573-1634
    Keywords: macroscale ; chemical potential ; mixture theory ; porous media ; swelling porous media
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Technology
    Notes: Abstract The thermodynamical relations for a two-phase, N-constituent, swelling porous medium are derived using a hybridization of averaging and the mixture-theoretic approach of Bowen. Examples of such media include 2-1 lattice clays and lyophilic polymers. A novel, scalar definition for the macroscale chemical potential for porous media is introduced, and it is shown how the properties of this chemical potential can be derived by slightly expanding the usual Coleman and Noll approach for exploiting the entropy inequality to obtain near-equilibrium results. The relationship between this novel scalar chemical potential and the tensorial chemical potential of Bowen is discussed. The tensorial chemical potential may be discontinuous between the solid and fluid phases at equilibrium; a result in clear contrast to Gibbsian theories. It is shown that the macroscopic scalar chemical potential is completely analogous with the Gibbsian chemical potential. The relation between the two potentials is illustrated in three examples.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006661330427
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  • 3
    Electronic Resource
    Electronic Resource
    Hydraulic radius and transport in reconstructed model three-dimensional porous media (1994)
    Springer
    Transport in porous media 17 (1994), S. 221-238 
    Details
    ISSN: 1573-1634
    Keywords: building technology ; conductivity ; critical diameter ; hydraulic radius ; permeability ; porous media ; reconstruction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Technology
    Notes: Abstract Methods for reconstructing three-dimensional porous media from two-dimensional cross sections are evaluated in terms of the transport properties of the reconstructed systems. Two-dimensional slices are selected at random from model three-dimensional microstructures, based on penetrable spheres, and processed to create a reconstructed representation of the original system. Permeability, conductivity, and a critial pore diameter are computed for the original and reconstructed microstructures to assess the validity of the reconstruction technique. A surface curvature algorithm is utilized to further modify the reconstructed systems by matching the hydraulic radius of the reconstructed three-dimensional system to that of the two-dimensional slice. While having only minor effects on conductivity, this modification significantly improves the agreement between permeabilities and critical diameters of the original and reconstructed systems for porosities in the range of 25–40%. For lower porosities, critical pore diameter is unaffected by the curvature modification so that little improvement between original and reconstructed permeabilities is obtained by matching hydraulic radii.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00613583
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  • 4
    Electronic Resource
    Electronic Resource
    Flow characteristics of anisotropic structures constructed with porous layers (1994)
    Springer
    Transport in porous media 15 (1994), S. 151-173 
    Details
    ISSN: 1573-1634
    Keywords: Anisotropic ; porous media ; flow characteristic ; permeability ; Forchheimer extension ; regression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Technology
    Notes: Abstract Artificial structures, serving as the solid matrix of anisotropic porous media and satisfying the requirement needed for flow visualization, were constructed with the perforated Polypropylene plates in order to improve the understanding of transport phenomena occurring in anisotropic porous media. This paper reports the regressed correlations of the experimental pressure gradient and filtration velocity data of three anisotropic and one isotropic porous media measured along two mutually orthogonal directions, which correspond to the principal axes of the permeability tensor, for the filtration velocities ranging from 0.2 to 12 mm/s with water as the fluid. To reflect the observed data, the regression equation with two types of deviations was formulated, in which the pressure gradient is represented by the sum of the linear and nonlinear terms of the filtration velocity. The physical model developed for the linear term assumes the solid matrix as repeated circular orifices when the filtration velocity approaches zero. The exponent of the filtration velocity in the nonlinear term was determined to be that of the Forchheimer extension. Also, four models for the coefficient of the nonlinear term were examined and the results were compared. The distribution of the residuals (the differences between the observed and the correlated values) validated the suggested regression procedure and the resulting correlations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00625514
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  • 5
    Electronic Resource
    Electronic Resource
    Estimation of three-phase relative permeabilities (1994)
    Springer
    Transport in porous media 16 (1994), S. 263-287 
    Details
    ISSN: 1573-1634
    Keywords: Three-phase flow ; relative permeabilities ; porous media ; residual saturation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Technology
    Notes: Abstract We have extended the Alemán-Slattery model to provide a self-consistent prediction for the residual saturation of the intermediate-wetting phase. Previous experimental studies of three-phase relative permeabilities are critiqued. Only a portion of the data of Oaket al. (J. Petrol. Tech. 42 (1990) 1054) and Oak (SPE/DOE 20183, Society of Petroleum Engineers, 1990) is regarded as suitable for comparison with available models. While the extended Alemán-Slattery model appears to give the best representation of these data, a definitive conclusion is premature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00617151
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  • 6
    Electronic Resource
    Electronic Resource
    Capillary end effect in a water saturated porous layer (1993)
    Springer
    Transport in porous media 13 (1993), S. 261-275 
    Details
    ISSN: 1573-1634
    Keywords: Oil-water flow ; porous media ; capillary end effect ; free imbibition ; Buckley-Leverett zone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Technology
    Notes: Abstract The uni-directional propagation of oil injected into water flowing through a water wetted porous slab of a finite length is investigated. The inlet and outlet edges of the slab are impermeable to the oil flux. Hence, the oil accumulates within the slab, thereby leading to a saturation build-up-capillary end effect. This phenomenon is studied analytically on the basis of a nonlinear equation describing oil-water transport in porous media. A dimensionless criterion is derived, which governs the appearance and relative strength of the capillary end effect. For weak oil-water interfacial tension (large capillary number) and long porous slabs the above effect is not observed and the temporal evolution of the oil saturation is described by the Buckley-Leverett solution. Short porous slabs are found to be almost entirely subjected to the capillary end effect. Intermediate situations are identified and quantitatively described, in which the downstream part of the slab may be divided into two zones: one-characterized by the capillary end effect, and the other being a Buckley-Leverett zone. It is shown, that the oil flux injected into the slab is limited by a maximum value which depends upon the location of the injection point. The partition of the inlet flux between the upstream and downstream directions is investigated. In the upstream side of the porous slab the oil moves under the action of free imbibition only. It is found that the upstream flux is limited by the value, which is independent of the slab's length and of the location of the injection point.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00622446
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  • 7
    Electronic Resource
    Electronic Resource
    A theory of macrodispersion for the scale-up problem (1993)
    Springer
    Transport in porous media 13 (1993), S. 97-122 
    Details
    ISSN: 1573-1634
    Keywords: Scale up ; dispersion ; porous media ; random field
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Technology
    Notes: Abstract Dispersion is the result, observable on large length scales, of events which are random on small length scales. When the length scale on which the randomness operates is not small, relative to the observations, then classical dispersion theory fails. The scale up problem refers to situations in which randomness occurs on all length scales, and for which classical dispersion theory necessarily fails. The purpose of this article is to present non-Fickian, theories of dispersion, which do not assume a scale separation between the randomness and the observed consequences, and which do not assume a single length scale. Porous media flow properties are heterogeneous on all length scales. The geological variation on length scales below the observational length scale can be regarded as unknown and unknowable, and thus as a random variable. We develop a systematic theory relating scaling behavior of the geological heterogeneity to the scaling behavior of the fluid dispersivity. Three qualitatively distinct regimes (Fickian, non-Fickian and nonrenormalizable) are found. The theory gives consistent answers within several distinct analytic approximations, and with numerical simulation of the equations of porous media flow. Comparison to field data is made. The use of Kriging to generate constrained ensembles for conditional simulation is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00613272
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  • 8
    Electronic Resource
    Electronic Resource
    Gravitational migration of fuel in porous media (1992)
    Springer
    Transport in porous media 9 (1992), S. 187-205 
    Details
    ISSN: 1573-1634
    Keywords: Two-phase flow ; buoyancy force ; porous media ; Bond number
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Technology
    Notes: Abstract Fuel migration in a water flowing through a porous medium generally occurs parallel to porous strata, which may not be horizontal. In this case, gravity tends to cause vertical segregation of fluids, depending on their densities. This phenomenon can exert a strong effect on fuel migration. The gravitational force creates the buoyancy force which acts upon the fuel, and may be either parallel or anti-parallel to the water flow direction. In this study, the above effects are investigated using the one-dimensional model of Pistineret al. We go beyond the latter investigation in describing the influence of the gravitational forces upon the movement of fuel saturation fronts in a vertical porous layer against and along the water flow direction. It is found that when the directions of the buoyancy force and of the water flow are anti-parallel, fuel migrates in the direction of the buoyancy force, provided the latter is strong enough. However, in the case of a weak buoyancy force, the direction of migration of the fuel depends on its mass. Small fuel masses move mainly in the direction of the water flow. However, big fuel slugs possessing large masses will move mainly in the direction of the buoyancy force. Slugs, characterized by intermediate masses, have no preferable moving direction and are almost stagnant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00611966
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  • 9
    Electronic Resource
    Electronic Resource
    Formulation of electro-chemico-osmotic processes in soils (1991)
    Springer
    Transport in porous media 6 (1991), S. 435-444 
    Details
    ISSN: 1573-1634
    Keywords: Electrokinetics ; electrophoresis ; electro-osmosis ; chemico-osmosis ; porous media ; transport processes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Technology
    Notes: Abstract Electrokinetic techniques have been used for various purposes including consolidation of soils, dewatering of sludges, and hazardous waste remediation among others. Estimating the feasibility of employing electro-osmosis in a particular operation depends on the ability to predict the outcome under a variety of conditions. Predictions of this type are frequently facilitated by the use of a mathematical model designed to represent the physical system under consideration in a rigorous fashion. First, a review of fundamental aspects of electro-chemico-osmotic flow in soils is presented. Following a brief outline of previous studies, identification and quantification of the significant processes, and the construction of mathematical representations are given. This is achieved using an approach based on the macroscopic conservation of mass equations and the principle of a continuum, in contrast to an approach based on the irreversible thermodynamics of coupled flows. Special emphasis is given to coupling effects on transport processes. A complete model and associated boundary conditions are then obtained for electrokinetic processes in a compressible porous medium. The proposed model takes into consideration the migration of a contaminant plume in a flow field generated by an applied electric potential.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00136350
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  • 10
    Electronic Resource
    Electronic Resource
    Effects of anisotropy on the free convection from a vertical plate embedded in a porous medium (1991)
    Springer
    Transport in porous media 6 (1991), S. 183-194 
    Details
    ISSN: 1573-1634
    Keywords: Free convection ; heat transfer ; porous media ; natural convection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Technology
    Notes: Abstract The effects of anisotropy on the steady laminar boundary-layer free convection over a vertical impermeable surface are analysed by using the method of integral relations. If the permeability in the direction orthogonal to the plate is greater than the permeability along the plate, then there is an increase in the temperature field.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00179280
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  • 11
    Electronic Resource
    Electronic Resource
    Scaling mixing during miscible displacement in heterogeneous porous media (1991)
    Springer
    Transport in porous media 6 (1991), S. 607-626 
    Details
    ISSN: 1573-1634
    Keywords: dispersion ; dispersivity ; heterogenity ; miscible ; porous media ; scaling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Technology
    Notes: Abstract This paper discusses scaling of mixing during miscible flow in heterogeneous porous media. In large field systems dispersivity appears to depend on system length due to heterogeneities. Three types of scaling are discussed to investigate the heterogeneous effects. Dimensional analysis of mixing during flow through geometerically scaled heterogeneous models is illustrated using measured dispersion. Fractal analysis of mixing in statistically scaled heterogeneous porous media is discussed. Analog scaling of pressure transients in heterogeneous porous media is suggested as an in-situ method of estimating dispersion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00137852
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  • 12
    Electronic Resource
    Electronic Resource
    Similarity solutions for immiscible phase migration in porous media: an analysis of free boundaries (1990)
    Springer
    Transport in porous media 5 (1990), S. 491-515 
    Details
    ISSN: 1573-1634
    Keywords: Two-phase flow ; fuel saturation ; self-similar solutions ; porous media ; convective dispersion ; capillary number
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Technology
    Notes: Abstract A fuel pollutant migrating in a water flow throughout a porous medium is distributed between the moving (continuous) and residual (discontinuous) phases. Usually, there is an equilibrium condition between these phases. In this study, the migration of a fuel slug confied within free boundaries moving in the porous medium is considered. This type of fuel migration pertains to circumstances in which convective fuel transport dominates fuel dispersion when fuel saturation approaches zero. A one-dimensional self-similar model is developed, describing the movement of fuel saturation fronts in a porous medium against and with the water flow direction. Several analytical solutions are found revealing the effects of the pore size, fuel viscosity, fuel mass, and the capillary number on the fuel migration in the porous medium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01403479
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  • 13
    Electronic Resource
    Electronic Resource
    Evolution of governing mass and momentum balances following an abrupt pressure impact in a porous medium (1990)
    Springer
    Transport in porous media 5 (1990), S. 169-185 
    Details
    ISSN: 1573-1634
    Keywords: Compressible fluid ; porous media ; abrupt pressure change ; time and spatial averaging ; mass and momentum balance equations ; nondimensional forms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Technology
    Notes: Abstract A mathematical model is developed of an abrupt pressure impact applied to a compressible fluid flowing through a porous medium domain. Nondimensional forms of the macroscopic fluid mass and momentum balance equations yield two new scalar numbers relating storage change to pressure rise. A sequence of four reduced forms of mass and momentum balance equations are shown to be associated with a sequence of four time periods following the onset of a pressure change. At the very first time period, pressure is proven to be distributed uniformly within the affected domain. During the second time interval, the momentum balance equation conforms to a wave form. The behavior during the third time period is governed by the averaged Navier-Stokes equation. After a long time, the fourth period is dominated by a momentum balance similar to Brinkman's equation which may convert to Darcy's equation when friction at the solid-fluid interface dominates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00144602
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  • 14
    Electronic Resource
    Electronic Resource
    Numerical experiments on convective heat transfer in water-saturated porous media at near-critical conditions (1990)
    Springer
    Transport in porous media 5 (1990), S. 299-323 
    Details
    ISSN: 1573-1634
    Keywords: Supercritical convection ; heat transfer ; numerical simulation ; porous media ; geothermal systems ; water ; critical point
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Technology
    Notes: Abstract Fluid and heat flow at temperatures approaching or exceeding that at the critical point (374 °C for pure water, higher for saline fluids) may be encountered in deep zones of geothermal systems and above cooling intrusives. In the vicinity of the critical point the density and internal energy of fluids show very strong variations for small temperature and pressure changes. This suggests that convective heat transfer from thermal buoyancy flow would be strongly enhanced at near-critical conditions. This has been confirmed in laboratory experiments. We have developed special numerical techniques for modeling porous flow at near-critical conditions, which can handle the extreme nonlinearities in water properties near the critical point. Our numerical simulations show strong enhancements of convective heat transfer at near-critical conditions; however, the heat transfer rates obtained in the simulations are considerably smaller than data reported from laboratory experiments by Dunn and Hardee. We discuss possible reasons for this discrepancy and develop suggestions for additional laboratory experiments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00140018
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  • 15
    Electronic Resource
    Electronic Resource
    Finite element modelling of two-phase heat and fluid flow in deforming porous media (1989)
    Springer
    Transport in porous media 4 (1989), S. 319-334 
    Details
    ISSN: 1573-1634
    Keywords: Finite elements ; consolidation ; porous media ; two-phase flow
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Technology
    Notes: Abstract This paper details a finite element model which describes the flow of two-phase fluid and heat within a deforming porous medium. The coupled governing equations are derived in terms of displacements, pore pressures and temperatures, and details of the time-stepping algorithm and thermodynamic considerations are also presented. Two numerical examples are included for verification.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00165778
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  • 16
    Electronic Resource
    Electronic Resource
    A coupled finite element model for the consolidation of nonisothermal elastoplastic porous media (1986)
    Springer
    Transport in porous media 1 (1986), S. 155-178 
    Details
    ISSN: 1573-1634
    Keywords: Three-field interaction problem ; temperature field ; flow field ; displacement field ; geothermal systems ; porous media ; elastoplastic analysis ; partitioned solution procedure ; fully coupled finite element models ; nonisothermal consolidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Technology
    Notes: Abstract A coupled finite element model for the analysis of the deformation of elastoplastic porous media due to fluid and heat flow is presented. A displacement-pressure temperature formulation is used for this purpose. This formulation results in an unsymmetric coefficient matrix, even in the case of associated plasticity. A partitioned solution procedure is applied to restore the symmetry of the coefficient matrix. The partitioning procedure is an algebraic one which is carried out after integration in the time domain. For this integration, a two-point recurrence scheme is used. The finite element model is applied to the investigation of nonisothermal consolidation in various situations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00714690
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