scholarly journals Porous Medium Typology Influence on the Scaling Laws of Confined Aquifer Characteristic Parameters

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1166 ◽  
Author(s):  
Carmine Fallico ◽  
Agostino Lauria ◽  
Francesco Aristodemo
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Hydraulic Conductivity ◽  
Scaling Laws ◽  
Scale Parameter ◽  
Effective Porosity ◽  
Coarse Grained ◽  
Characteristic Parameters ◽  
Porous Aquifer ◽  
Aquifer Characteristic

An accurate measurement campaign, carried out on a confined porous aquifer, expressly reproduced in laboratory, allowed the determining of hydraulic conductivity values by performing a series of slug tests. This was done for four porous medium configurations with different granulometric compositions. At the scale considered, intermediate between those of the laboratory and the field, the scalar behaviors of the hydraulic conductivity and the effective porosity was verified, determining the respective scaling laws. Moreover, assuming the effective porosity as scale parameter, the scaling laws of the hydraulic conductivity were determined for the different injection volumes of the slug test, determining a new relationship, valid for coarse-grained porous media. The results obtained allow the influence that the differences among the characteristics of the porous media considered exerted on the scaling laws obtained to be highlighted. Finally, a comparison was made with the results obtained in a previous investigation carried out at the field scale.

scholarly journals Comparison among variation models of the hydraulic conductivity with the effective porosity in confined aquifer

2021 ◽  
Vol 958 (1) ◽  
pp. 012003
Author(s):  
G F A Brunetti ◽  
A Lauria ◽  
C Fallico
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Hydraulic Conductivity ◽  
Scaling Laws ◽  
Scaling Law ◽  
Graphical Analysis ◽  
Coarse Sand ◽  
Effective Porosity ◽  
Confined Aquifer ◽  
Semi Empirical

Abstract This paper presents the experimental investigation results from the modalities of variation of the hydraulic conductivity scaling law for a confined aquifer, varying the porous medium that constitutes it. In four subsequent stages, different confined aquifers were built up, each with a different typological configuration of a porous medium. For each of the aquifers considered, various hydraulic conductivity (K) measurements were performed by slug tests. The effective porosity (ne ) was set as a scale parameter, therefore the scaling laws K = K(ne), already determined and reported in previous studies, were taken into consideration for each of the four artificial aquifers considered. The same variation law of K vs ne was also determined by means of some of the well-known empirical and semi-empirical relationships. The latter are based on the particle size distribution and are suitable for application to the porous media considered here, which can be classified as coarse sand. The comparison between the different scaling laws mentioned above allowed us to discuss, through graphical analysis, the reliability of the models considered here. This will facilitate researchers and practitioners working in the field, in the methodological choice of the most appropriate model that should be used for this type of porous media.

SHOCK PROPAGATION IN A FLOW THROUGH DEFORMABLE POROUS MEDIA: ASYMPTOTIC BEHAVIOUR AS THE POROSITY APPROXIMATES A CONSTANT

2007 ◽  
Vol 17 (08) ◽  
pp. 1261-1278
Author(s):  
ELENA COMPARINI ◽  
MAURA UGHI
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Hydraulic Conductivity ◽  
Asymptotic Behaviour ◽  
Incompressible Flow ◽  
Shock Propagation ◽  
One Dimensional ◽  
Deformable Porous Media ◽  
Flux Intensity ◽  
Flow Through

We consider a one-dimensional incompressible flow through a porous medium undergoing deformations such that the porosity and the hydraulic conductivity can be considered as functions of the flux intensity. We prove that if one approximates the porosity with a constant then the solution of the hyperbolic problem converges to the classical continuous Green–Ampt solution, also in the presence of shocks. In general, however, the shocks remain present in any approximating solution.

scholarly journals Coarse-Grained Geological Porous Media Structure Modeling Using Heuristic Algorithm and Evaluation of Porosity, Hydraulic Conductivity, and Pressure Drop with Experimental Results

2021 ◽  
Author(s):  
Javad Bezaatpour ◽  
Esmaeil Fatehifar ◽  
Ali Rasoulzadeh
Keyword(s):  
Particle Size ◽  
Porous Media ◽  
Hydraulic Conductivity ◽  
Pressure Drop ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Heuristic Algorithm ◽  
Flow In Porous Media ◽  
Coarse Grained ◽  
Water Retention Curve

Abstract Knowledge of porous media structure is an essential part of the hydrodynamic investigation of fluid flow in porous media. To study soil behavior (as a granular porous media) and water and contaminant movement in the vadose zone, appropriate estimation of soil water retention curve (SWRC) and soil hydraulic conductivity curve (SHCC) has a pivotal role and is one of the most challenging topics for researchers and engineers in soil and water science. The SWCR can be approximated using an accurate particle size distribution (PSD) function. In this study by applying random close packing (RCP) method as an encouraging method for predicting and studying particle configuration, an optimal particle size distribution is developed for coarse-grained soils (0.025 mm < PSD < 3.35mm). The mentioned RCP is generated using heuristic algorithm with merging applicable equations of soil science. For porous media modeling, MATLAB software is used and the predicted results by the optimal model for the parameters of porosity, pressure drop, and saturated hydraulic conductivity are compared with laboratory measurements. Experimental design is conducted by MINITAB and predicted coarse-grained soils structure by the model is compared with 4 sifted soils. The results of the sensitivity analysis showed that the porosity obtained from the model is strongly sensitive to the resolution factor and should be chosen with a sufficiently large amount (higher than 250). Results showed good consistency (up to 95%) between predicted porosity and only 10% difference in pressure drop and permeability with observed measurements.

scholarly journals Influence of the scale range width on the determination of the hydraulic conductivity and effective porosity. The case of a porous aquifer in southern Italy

2019 ◽  
Vol 11 (2) ◽  
Author(s):  
Carmine Fallico ◽  
Samuele De Bartolo ◽  
María Fernanda Rivera-Velasquez ◽  
Mario Ianchello
Keyword(s):  
Hydraulic Conductivity ◽  
Scaling Laws ◽  
Scaling Law ◽  
Original Data ◽  
Effective Porosity ◽  
Data Sets ◽  
Test Field ◽  
Single Scale ◽  
Scale Range ◽  
Measurement Uncertainties

AbstractThe importance of a law that, for an assigned porous medium, gives the variability of the hydraulic conductivity with the effective porosity is well known. Commonly this variability is represented by a power law at different scales, especially those of laboratory and field. Often it can be useful to have a scaling law valid for a single scale range, comprising both those of laboratory and field. Therefore investigation about the reliability of the laws representing the scaling behavior in the various intervals to which reference was made could be suitable.The purpose of this study is to provide evidence about the reliability of the scaling laws for laboratory, field and global (laboratory plus field) scaling ranges, verifying consistency with the expected proportionality between hydraulic conductivity and effective porosity for each of these. This verification was carried out using power-type scaling laws to two and four parameters respectively, and performing suitable moving averages of original data sets, in an attempt to reduce the inevitable measurement uncertainties. The experimental results, obtained with reference to the confined aquifer of Montalto Uffugo test field, show that there are no significant differences between the scaling laws considered and highlight the need to reduce the measurement uncertainties, which weigh heavily on the reliability of scaling laws. Keywords: Scaling law; Hydraulic conductivity; Effective porosity; Laboratory measurement, Field measurement. INFLUENCIA DE LA AMPLITUD DEL INTERVALO DE ESCALA EN LA DETERMINACIÓN DE LA CONDUCTIVIDAD HIDRÁULICA Y LA POROSIDAD EFECTIVA. EL CASO DE UN ACUÍFERO POROSA DEL SUR DE ITALIA La importancia de una ley que, para un dado medio poroso, describa la variabilidad de la conductividad hidráulica en función de la porosidad efectiva es bien conocida. Frecuentemente esta variabilidad está representada por una ley de potencia a diferentes escalas, especialmente las de laboratorio y de campo. A menudo es útil tener una ley de escalamiento válida para un cierto rango de escala incluyendo los de laboratorio y campo. Por esta razón, es oportuno investigar la confiabilidad de las leyes que representan este comportamiento de escalamiento en los diferentes intervalos a los cuales típicamente se hace referencia. El propósito de este estudio es proporcionar evidencia sobre la confiabilidad de las leyes de escalamiento para intervalos de escala válidos para laboratorio, campo y globales (laboratorio + campo), verificando la consistencia con la proporcionalidad esperada entre la conductividad hidráulica y la porosidad efectiva para cada uno de estos. Esta verificación se llevó a cabo utilizando leyes de escalamiento de potencia para dos y cuatro parámetros respectivamente, y tratando de reducir las inevitables incertidumbres de medición. Los resultados experimentales obtenidos con referencia al acuífero confinado del campo de prueba Montalto Uffugo, muestran que no hay diferencias significativas entre las leyes de escalamiento consideradas y se destaca la necesidad de reducir las incertidumbres de medición, las cuales tienen un alto peso sobre la fiabilidad de las leyes de escala. Palabras clave: ley de escalamiento; Conductividad hidráulica; porosidad efectiva; mediciones de laboratorio, medición de campo. 

Numerical Approach to Statistical Mechanics of Surfactants in Porous Media: A Coarse Grained Description

1997 ◽  
Vol 08 (06) ◽  
pp. 1335-1343
Author(s):  
Prabal K. Maiti ◽  
Debashish Chowdhury
Keyword(s):  
Monte Carlo Simulation ◽  
Porous Medium ◽  
Porous Media ◽  
Monte Carlo ◽  
Numerical Scheme ◽  
Numerical Approach ◽  
Coarse Grained ◽  
Vycor Glass ◽  
Oil Water ◽  
Dynamical Scheme

We present a numerical scheme for Monte Carlo Simulation (MC) of ternary microemulsions, which consist of oil, water and surfactants, confined inside a porous medium such as vycor glass. The model porous medium has been created using the Cell Dynamical Scheme (CDS) while the microemulsion has been modeled following the Larson prescription.

scholarly journals The kinetics of ice-lens growth in porous media

2012 ◽  
Vol 692 ◽  
pp. 482-498 ◽  
Author(s):  
Robert W. Style ◽  
Stephen S. L. Peppin
Keyword(s):  
Growth Rate ◽  
Porous Medium ◽  
Porous Media ◽  
Coarse Grained ◽  
Interfacial Resistance ◽  
Significant Drop ◽  
Ice Growth ◽  
External Pressures ◽  
Lens Growth ◽  
Kinetics Of

AbstractWe analyse the growth rate of segregated ice (ice lenses) in freezing porous media. For typical colloidal materials such as soils we show that the commonly employed Clapeyron equation is not valid macroscopically at the interface between the ice lens and the surrounding porous medium owing to the viscous dynamics of flow in premelted films. The flow in these films gives rise to an ‘interfacial resistance’ to flow towards the growing ice which causes a significant drop in predicted ice-growth (heave) rates. This explains why many previous models predict ice-growth rates that are much larger than those seen in experiments. We derive an explicit formula for the ice-growth rate in a given porous medium, and show that this only depends on temperature and on the external pressures imposed on the freezing system. This growth-rate formula contains a material-specific function which can be calculated (with knowledge of the geometry and material of the porous medium), but which is also readily experimentally measurable. We apply the formula to plate-like particles, and show that the results can be matched with previous experimental data. Finally we show how the interfacial resistance explains the observation that the maximum heave rate in soils occurs in medium-grained particles such as silts, while heave rates are smaller for fine- and coarse-grained particles.

Unsaturated flow in coarse porous media

2005 ◽  
Vol 42 (1) ◽  
pp. 252-262 ◽  
Author(s):  
Jeff R Reinson ◽  
Delwyn G Fredlund ◽  
G Ward Wilson
Keyword(s):  
Porous Media ◽  
Hydraulic Conductivity ◽  
Soil Water ◽  
Unsaturated Soils ◽  
Unsaturated Flow ◽  
Characteristic Curve ◽  
Matric Suction ◽  
Coarse Grained ◽  
Capillary Barrier ◽  
Coarse Porous Media

Design of effective capillary barrier systems requires a thorough understanding of the soil–water interactions that take place in both coarse- and fine-grained unsaturated soils. Experimental observations of water flow through coarse porous media are presented to gain greater understanding of the processes and mechanisms that contribute to the movement and retention of water in coarse-grained unsaturated soils. The use of pendular ring theory to describe how water is held within a porous material with relatively low volumetric water contents is explored. Experimental measurements of seepage velocity and volumetric water content were obtained for columns of 12 mm glass beads using digital videography to capture the movement of a dye tracer front at several infiltration rates. An estimated curve for hydraulic conductivity versus matric suction is shown and compared to a theoretical curve. The method is shown to provide a reasonable predictive tool.Key words: soil-water characteristic curve, hydraulic conductivity curve, water permeability function, capillary barrier, matric suction.

Siphon Flows in Stratified Coronal Loops

1994 ◽  
Vol 144 ◽  
pp. 185-187
Author(s):  
S. Orlando ◽  
G. Peres ◽  
S. Serio
Keyword(s):  
Heat Flux ◽  
Scaling Laws ◽  
Flow Model ◽  
Supersonic Flows ◽  
Coronal Loops ◽  
Characteristic Parameters

AbstractWe have developed a detailed siphon flow model for coronal loops. We find scaling laws relating the characteristic parameters of the loop, explore systematically the space of solutions and show that supersonic flows are impossible for realistic values of heat flux at the base of the upflowing leg.

Conservative solute transport with periodic velocity and sinusoidal source concentration in semi-infinite porous media: An analytical solution

2014 ◽  
Vol 6 (1) ◽  
pp. 1024-1031
Author(s):  
R R Yadav ◽  
Gulrana Gulrana ◽  
Dilip Kumar Jaiswal
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Laplace Transformation ◽  
Seepage Velocity ◽  
Transformation Technique ◽  
Numerical Examples ◽  
One Dimensional ◽  
Porous Domain ◽  
Conservative Solute Transport ◽  
Source Concentration

The present paper has been focused mainly towards understanding of the various parameters affecting the transport of conservative solutes in horizontally semi-infinite porous media. A model is presented for simulating one-dimensional transport of solute considering the porous medium to be homogeneous, isotropic and adsorbing nature under the influence of periodic seepage velocity. Initially the porous domain is not solute free. The solute is initially introduced from a sinusoidal point source. The transport equation is solved analytically by using Laplace Transformation Technique. Alternate as an illustration; solutions for the present problem are illustrated by numerical examples and graphs.

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