NMR imaging of flow velocity in porous media

AIChE Journal ◽  
1999 ◽  
Vol 45 (3) ◽  
pp. 437-444 ◽  
Author(s):  
C. T. Philip Chang ◽  
A. Ted Watson
Keyword(s):  
Porous Media ◽  
Flow Velocity ◽  
Nmr Imaging

Unsteady and porous media flow of reactive non-Newtonian fluids subjected to buoyancy and suction/injection

2015 ◽  
Vol 25 (7) ◽  
pp. 1682-1704 ◽  
Author(s):  
Tirivanhu Chinyoka ◽  
Daniel Oluwole Makinde
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Boundary Conditions ◽  
Flow Velocity ◽  
Flow System ◽  
Finite Difference Methods ◽  
Porous Media Flow ◽  
Convective Boundary Conditions ◽  
Convective Boundary ◽  
Content Type

Purpose – The purpose of this paper is to examine the unsteady pressure-driven flow of a reactive third-grade non-Newtonian fluid in a channel filled with a porous medium. The flow is subjected to buoyancy, suction/injection asymmetrical and convective boundary conditions. Design/methodology/approach – The authors assume that exothermic chemical reactions take place within the flow system and that the asymmetric convective heat exchange with the ambient at the surfaces follow Newton’s law of cooling. The authors also assume unidirectional suction injection flow of uniform strength across the channel. The flow system is modeled via coupled non-linear partial differential equations derived from conservation laws of physics. The flow velocity and temperature are obtained by solving the governing equations numerically using semi-implicit finite difference methods. Findings – The authors present the results graphically and draw qualitative and quantitative observations and conclusions with respect to various parameters embedded in the problem. In particular the authors make observations regarding the effects of bouyancy, convective boundary conditions, suction/injection, non-Newtonian character and reaction strength on the flow velocity, temperature, wall shear stress and wall heat transfer. Originality/value – The combined fluid dynamical, porous media and heat transfer effects investigated in this paper have to the authors’ knowledge not been studied. Such fluid dynamical problems find important application in petroleum recovery.

scholarly journals An experimental study on the determination of dispersion coefficient in layered soils

2021 ◽  
Author(s):  
Hamed Mahdipanah ◽  
Askari Tashakori ◽  
Samad Emamgholizadeh ◽  
Eisa Maroufpoor
Keyword(s):  
Porous Media ◽  
Flow Velocity ◽  
Sampling Method ◽  
Travel Distance ◽  
Coarse Grained ◽  
Contaminant Concentration ◽  
Fine Grained ◽  
Sodium Chloride Solutions ◽  
Heterogeneous Soils ◽  
Homogeneous Soil

Abstract Dispersivity is a measurable parameter in soil porous media that is used for studying the transport of contaminants to groundwater. The value of this parameter depends on various factors, including the kind of porous media (homogeneous or heterogeneous), flow velocity, initial contaminant concentration, travel distance, and sampling method. A physical model with dimensions of 0.10 m in width, 0.80 m in height, and 1.10 m in length was constructed to investigate the effects of these parameters on the dispersivity value. The stratified soil consisted of three 20-cm-thick layers containing fine-grained, medium-grained, and coarse-grained soil. Sodium chloride solutions with electrical conductivity values of 10, 14, and 19 dS/m were used as the contaminants. Flow was forced through the layered heterogeneous soils at three discharge velocities of 17.58, 22.02, and 26.18 × 10−5 m/s. The point and mixed sampling methods were used. The results indicated that the soil dispersivity values in the layered heterogeneous soils and homogeneous soil were influenced by contaminant concentration, flow velocity, and travel distance. Moreover, the dispersivity values obtained by point sampling were lower than those obtained using the mixed sampling method, and the mean dispersivity value in the layered heterogeneous soils was lower than that of the homogeneous soil.

scholarly journals High-speed NMR imaging of capillary action in thin nontransparent porous media

2021 ◽  
Vol 104 (4) ◽  
Author(s):  
R. Nicasy ◽  
H. P. Huinink ◽  
S. J. F. Erich ◽  
O. C. G. Adan
Keyword(s):  
Porous Media ◽  
High Speed ◽  
Nmr Imaging ◽  
Capillary Action

scholarly journals The Hydrodynamic Dispersion Characteristics of Coral Sands

2019 ◽  
Vol 7 (9) ◽  
pp. 291 ◽  
Author(s):  
Xiang Cui ◽  
Changqi Zhu ◽  
Mingjian Hu ◽  
Xinzhi Wang ◽  
Haifeng Liu
Keyword(s):  
Particle Size ◽  
Porous Media ◽  
Flow Velocity ◽  
Molecular Diffusion ◽  
Dispersion Coefficient ◽  
Hydrodynamic Dispersion ◽  
Dispersion Characteristics ◽  
Factors Affecting ◽  
Mechanical Dispersion ◽  
Freshwater Aquifers

Dispersion characteristics are important factors affecting groundwater solute transport in porous media. In marine environments, solute dispersion leads to the formation of freshwater aquifers under islands. In this study, a series of model tests were designed to explore the relationship between the dispersion characteristics of solute in calcareous sands and the particle size, degree of compactness, and gradation of porous media, with a discussion of the types of dispersion mechanisms in coral sands. It was found that the particle size of coral sands was an important parameter affecting the dispersion coefficient, with the dispersion coefficient increasing with particle size. Gradation was also an important factor affecting the dispersion coefficient of coral sands, with the dispersion coefficient increasing with increasing d10. The dispersion coefficient of coral sands decreased approximately linearly with increasing compactness. The rate of decrease was −0.7244 for single-grained coral sands of particle size 0.25–0.5 mm. When the solute concentrations and particle sizes increased, the limiting concentration gradients at equilibrium decreased. In this study, based on the relative weights of molecular diffusion versus mechanical dispersion under different flow velocity conditions, the dispersion mechanisms were classified into five types, and for each type, a corresponding flow velocity limit was derived.

NMR Imaging of Multiphase Flow in Porous Media

1992 ◽  
Author(s):  
Songhua Chen ◽  
Fangfang Qin ◽  
K-H. Kim ◽  
A.T. Watson
Keyword(s):  
Porous Media ◽  
Multiphase Flow ◽  
Flow In Porous Media ◽  
Nmr Imaging

Article

1998 ◽  
Vol 76 (11) ◽  
pp. 1633-1641
Author(s):  
Luc Tremblay ◽  
Serge Lacelle ◽  
Charles G Fry
Keyword(s):  
Porous Media ◽  
Pyrex Glass ◽  
Nmr Imaging ◽  
Porous Network ◽  
Intensity Correlation ◽  
Geometric Means ◽  
Statistical Characterization ◽  
One Dimensional ◽  
Intensity Fluctuations ◽  
The One

A study of the intensity fluctuations in one-dimensional NMR microimaging profiles of imbibed porous Pyrex glass filters is presented. An approach to characterize some aspects of the macroscopic randomness from the NMR microimaging profiles of this porous medium is developed. Statistical properties, such as the arithmetic and geometric means, of the distributions of peak separations between the intensity fluctuations are shown to reveal information about the pore size and the pore-to-pore distances in porous media. The intensity-intensity correlation functions of the one-dimensional NMR profiles display an interplay, as a function of length scale, among the dimensions of the porous network and its embedding space, and their respective dimensions in the projections. Corroboration of these NMR results are achieved with similar analysis of SEM two-dimensional images and their corresponding one-dimensional projections obtained with the same porous Pyrex glass. The approach developed to characterize the macroscopic randomness in these porous glass filters should prove generic for the study of other random materials.Key words: NMR imaging, scanning electron microscopy, porous media, disorder, statistical characterization.

NMR imaging applied to various studies of porous media

1991 ◽  
Vol 9 (5) ◽  
pp. 821-825 ◽  
Author(s):  
G. Guillot ◽  
A. Trokiner ◽  
L. Darrasse ◽  
A. Dupas ◽  
F. Ferdossi ◽  
...  
Keyword(s):  
Porous Media ◽  
Nmr Imaging

scholarly journals Colloid release and clogging in porous media: Effects of solution ionic strength and flow velocity

2015 ◽  
Vol 181 ◽  
pp. 161-171 ◽  
Author(s):  
Saeed Torkzaban ◽  
Scott A. Bradford ◽  
Joanne L. Vanderzalm ◽  
Bradley M. Patterson ◽  
Brett Harris ◽  
...  
Keyword(s):  
Porous Media ◽  
Ionic Strength ◽  
Flow Velocity ◽  
Media Effects ◽  
Solution Ionic Strength
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