Begell House Inc.
Journal of Porous Media
JPM
1091-028X
21
6
2018
THE SIMULATION OF VISCOUS FINGERING BY USING A DIFFUSION-LIMITED-AGGREGATION MODEL DURING CO2 FLOODING
483-497
10.1615/JPorMedia.v21.i6.10
Wei
Tian
Department of Modern Mechanics, University of Science and Technology of China, Hefei
230027, Anhui, China
Peichao
Li
School of Mechanical and Automotive Engineering, Shanghai University of Engineering
Science, Shanghai 201620, China
Yaoge
Liu
Department of Modern Mechanics, University of Science and Technology of China, Hefei
230027, Anhui, China
Zhiwei
Lu
McDougall School of Petroleum Engineering, University of Tulsa, Tulsa, OK
Detang
Lu
Department of Modern Mechanics, University of Science and Technology of China, Hefei 230027, P. R. China
viscous fingering
DLA
3D digital core
corrosion
CO2 flooding
Under the conditions of high temperature and high pressure, viscous fingering phenomenon occurs during CO2 flooding because of viscosity differences between CO2 and crude oil, which leads to premature breakthrough of displacement fluid and the decrease of sweep efficiency. Therefore, oil production cannot reach the expected yields. In this paper, we investigate the effect of viscosity ratio, injection rate, and pore structure on viscous fingering in 3D digital cores obtained by CT experiments based on a diffusion-limited-aggregation (DLA) model. The results show that viscosity difference is the dominating factor that influences viscous fingering. With the increase of viscosity difference between the two displacement fluids, sweep efficiency decreases dramatically. In a lower permeable reservoir and at an appropriate injection rate, the viscous fingering can be decreased. The numerical simulation is validated against the CO2 flooding experiment.
TORSIONAL SURFACE WAVE PROPAGATION IN AN IMPERFECTLY BONDED CORRUGATED INITIALLY-STRESSED POROELASTIC SANDWICHED LAYER
499-522
10.1615/JPorMedia.v21.i6.20
Abhishek Kumar
Singh
Department of Mathematics, Vellore Institute of Technology, Chennai-600127, India
Anirban
Lakshman
Department of Mathematical Sciences, IIT(BHU), Varanasi-221005, Uttar Pradesh, India
Kshitish Ch.
Mistri
Department of Applied Mathematics, IIT(ISM), Dhanbad-826004, Jharkhand, India
Mukesh Kumar
Pal
Department of Applied Mathematics, IIT(ISM), Dhanbad-826004, Jharkhand, India
imperfect bonding
poroelastic
viscoelastic
dry sandy
initial stress
corrugated
The aim of the present study is to investigate the propagation of torsional surface waves in an initially stressed poroelastic
layer with corrugated as well as loosely bonded boundary surfaces, sandwiched between an upper initially stressed
gravitating dry sandy Gibson half-space and a lower initially stressed viscoelastic half-space. The problem is solved
analytically with a view to obtain a solution whose real part provides the dispersion equation and imaginary part gives
the damped equation in their closed forms. As a special case of the problem, it is found that deduced dispersion relation
is found in good agreement with the classical Love wave equation and the damping equation vanishes identically. The
effect of imperfectly bonded interfaces, sandiness, heterogeneity, gravity, internal friction due to viscoelasticity, initial
stresses, porosity and corrugation on the phase velocity, and damped velocity of torsional surface wave has been studied
numerically and demonstrated graphically. The comparative study has been made to discuss the cases of welded contact,
smooth contact, loose bonding, and planar boundaries of the sandwiched layer. Moreover, the study of the effect of
presence and absence of sandiness, porosity, viscoelasticity, and initial stresses on the propagation of torsional surface
waves are also highlighted in the study.
ENTROPY GENERATION ANALYSIS FOR MHD FLOW THROUGH A VERTICAL DEFORMABLE POROUS LAYER
523-538
10.1615/JPorMedia.v21.i6.30
S.
Sreenadh
Department of Mathematics, Sri Venkateswara University, Tirupati, Andhra Pradesh, India-517502
G. Gopi
Krishna
Department of Mathematics, Sri Venkateswara University, Tirupati, A.P., India
A. N. S.
Srinivas
Department of Mathematics, School of Advanced Sciences, VIT University, Vellore, India
E.
Sudhakara
Department of BS and H, Siddhartha Institute of Engineering and Technology, Puttur, India
MHD
natural convection
deformable porous layer
heat source
entropy generation
The present study investigates the entropy generation analysis for magnetohydrodynamics (MHD) flow of a viscous
fluid through a deformable vertical porous layer. The bounding vertical plates y = 0 and y = h are maintained at
different constant temperatures T0 and Tw, respectively. The coupled phenomenon of the fluid movement and solid
deformation in the porous medium are considered. Governing equations are deduced for the fluid velocity and solid
displacement in the vertical deformable porous medium. The solutions in closed form for the fluid velocity, solid displacement, and temperature distribution are derived. Significant results are observed for different values of pertinent parameters, such as magnetic parameter, drag coefficient, and volume fraction of fluid in the porous layer. A table of comparison is made to study the effect of magnetic parameter on three different cases of volume flow rates Q1, Q2, and Q. It is noted that the volume flow rate in the deformable porous medium decreases with increasing magnetic parameter, since magnetic field reduces the fluid velocity. One of the important observations is that the flux is less for a deformable porous layer when compared to the free flow and rigid porous layer. The results coincide with the observations made by Wen et al. (Wen, P.H., Hon, Y.C., and Wang, W., Appl. Math. Modell., vol. 33, no. 1, pp. 423–436, 2009) and Barry et al. (Barry, S.I., Parker, K.H., and Aldis, G.K., J. Appl. Math. Phys., vol. 42, no. 5, pp. 633–648, 1991). The results obtained for the present flow characteristics reveal many interesting behaviors that warrant further study on the deformable porous media. The influence of drag coefficient on the entropy generation number and Bejan number was quite significant.
COMPUTATIONAL FLUID DYNAMICS SIMULATION OF MOVING-BED NANOCATALYTIC CRACKING PROCESS FOR THE LIGHTENING OF HEAVY CRUDE OIL
539-553
10.1615/JPorMedia.v21.i6.40
Mohammad
Ahmadlou
Faculty of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic),
Tehran, Iran
Mashallah
Rezakazemi
Faculty of Chemical and Materials Engineering, Shahrood University of Technology, Shahrood,
P.O. Box 3619995161 Iran
CFD
modeling
nanocatalyst
mass transfer
lightening
heavy crude oil
Lightening of heavy crude oil was studied theoretically using moving-bed nanocatalytic cracking process in this study. Based on the reaction mechanisms and the formulation of heavy crude oil, the five-lumped model was considered.
Computational fluid dynamics (CFD) technique was used to solve the model equations. In this reactor, the nanocatalyst
bed moves at a constant velocity (0.007 m/s) in co-current configuration with feed flow way (heavy crude oil). The
feed-reactive component gets involved in the reaction after penetrating through the nanocatalyst. Heavy crude oil was
considered as five components. The heavier components are directly converted to the lightest components. From CFD
simulation results, it was found that an increase in the velocity of heavy oil feeding reduces the velocity of heavy
components' conversion into lighter ones. Moreover, increasing the velocity of the moving bed leads to increase the efficiency (conversion) of the process since it causes a contact between the feed and the fresh nanocatalyst, and also reduces the coke on the nanocatalyst. 99% conversion rate based on 0.1125 mol/m3 initial concentration and 5 cm/s feed velocity was obtained in the lightening of heavy crude oil using moving-bed nanocatalytic cracking.
THERMOPHORESIS AND HEAT GENERATION/ABSORPTION EFFECTS ON MAGNETOHYDRODYNAMIC FLOW OF JEFFREY FLUID OVER POROUS OSCILLATORY STRETCHING SURFACE WITH CONVECTIVE BOUNDARY CONDITIONS
555-576
10.1615/JPorMedia.v21.i6.50
Sami Ullah
Khan
Department of Mathematics, COMSATS University Islamabad Sahiwal Campus, Sahiwal
57000, Pakistan
Nasir
Ali
Department of Mathematics and Statistics, International Islamic University, Islamabad 44000, Pakistan
thermophoresis effects
heat generation/absorption
oscillatory stretching sheet
homotopy analysis method
In the current work, the effects of thermophoresis, heat generation/absorption, chemical reaction, and thermal radiation on two-dimensional boundary layer flow of a Jeffrey fluid over an oscillatory stretching surface embedded in a porous medium are investigated. Unlike typical studies, the idea of convective boundary conditions is used to investigate heat and mass transfer phenomenon. With the help of appropriate dimensionless variables, the number of independent variables is reduced in the governing equations, which are then solved analytically by using the homotopy analysis method. The effects of involved physical parameters such as Deborah number, ratio of relaxation to retardation time, Hartmann number, Prandtl number, heat absorption/generation parameter, thermal and concentration and Biot numbers, chemical reaction parameter, Schmidt number and thermophoresis parameter on dimensionless velocity, temperature, and concentration distributions are investigated and discussed quantitatively with the help of various graphs. It is observed that amplitude of oscillations in velocity increases with increasing Deborah number while it follows an opposite trend with increasing porosity parameter. Moreover, the heat transfer increases with increasing porosity parameter and ratio of relaxation to retardation time while it decreases with increasing Deborah number.