Begell House
Journal of Porous Media
Journal of Porous Media
1091-028X
14
7
2011
SORPTION KINETICS MODEL APPLICATION ON THE MEASUREMENT OF WATER VAPOR PERMEABILITY IN BUILDING MATERIALS
This work proposes a simple experimental technique that provides a method, based on sorption kinetics, for the measurement of water vapor permeability of building materials. It is a novel method that has the added interest of easily providing data in a few hours using a dynamic process of moisture absorption based on a pseudo-second-order kinetic model. Experimental measurements of water vapor permeability covering four different types of building materials were carried out for a range of the relevant parameters, such as temperature and relative humidity. The experimental results obtained are in good agreement with the experimental values of the water vapor permeability measured by our team and other researchers using the classic standard cup method; and the results showed that the moisture buffer performance, from a different step of relative humidity, can be predicted with the knowledge of previous values and the kinetics parameters specific to a material using the equations proposed in this work.
J.M.P.Q.
Delgado
CONSTRUCT-LFC, Departamento de Engenharia Civil, Universidade do Porto Rua Dr. Roberto Frias, s/n; 4200-465 Porto, Portugal
Nuno M. M.
Ramos
Laboratório de Física das Construções (LFC), Departamento de Engenharia Civil, Universidade do Porto
V. P.
de Freitas
CONSTRUCT-LFC, Departamento de Engenharia Civil, Universidade do Porto Rua Dr. Roberto Frias, s/n; 4200-465 Porto, Portugal
565-578
TWO-PHASE FLOW OF AN OIL-WATER SYSTEM IN POROUS MEDIA WITH COMPLEX GEOMETRY INCLUDING WATER FLOODING: MODELING AND SIMULATION
The purpose of the present work is to obtain a numerical solution for the two-dimensional black-oil model applied to the two-phase flow (water-oil) inside a reservoir with complex geometry including water flooding as an enhanced oil recovery process. The model can be applied to studies in reservoirs that contain heavy oils or low-volatility hydrocarbons. The mass conservation equations written in the mass fraction formulation and boundary-fitted coordinates incorporate variable permeability and mobility effects, and are solved using the finite-volume method, with a fully implicit methodology and Newton's method. Calculations of the hydrodynamic parameters of an oil-water reservoir element are carried out for several cases involving water flooding. The results of the fluid saturation fields, water cut, oil recovery, and pressure distribution inside the reservoir over time are presented and analyzed. This study shows that water flooding yields faster recovery and is an efficient exploitation method of reservoir fluid production.
Francisco Alves
Batista
Departamento de Física, Universidade Estadual da Paraíba (UEPB)
Brauner Gongalves
Coutinho
Departamento de Física, Universidade Estadual da Paraíba (UEPB)
Francisco
Marcondes
Departamento de Engenharia Metalúrgica e Ciencias dos Materiais, Universidade Federal do Ceará
Severino Rodrigues de Farias
Neto
Departamento de Engenharia Mecânica, Centro de Ciências e Tecnologia, Universidade Federal de Campina Grande (UFCG)
Antonio Gilson Barbosa
de Lima
Departamento de Engenharia Mecânica, Centro de Ciências e Tecnologia, Universidade Federal de Campina Grande (UFCG)
579-592
HEAT AND MASS DIFFUSION AND SHRINKAGE IN PROLATE SPHEROIDAL BODIES BASED ON NON-EQUILIBRIUM THERMODYNAMICS: A NUMERICAL INVESTIGATION
The diffusion phenomenon exists in many industrial applications such as in the drying, wetting, heating, and cooling of solids, and principally in biological products such as in foodstuffs (grains, fruits, vegetables, etc.). In this sense, a new mathematical formulation to describe the simultaneous heat and mass (liquid and vapor) transfer and shrinkage during drying of capillary-porous bodies, with particular reference to prolate spheroid solids, is presented. The mathematical model was based on non-equilibrium thermodynamics considering variable transport coefficients and convective boundary conditions at the surface of the solid, including dimension variations. All of the governing equations presented in the model are written in prolate spheroidal coordinates and solved numerically by the finite-volume method using fully implicit formulation. An application of the methodology was used to predict drying of wheat kernel. Results on drying and heating kinetics, and on the moisture content and temperature distributions in a wheat kernel during the drying process, are presented and analyzed. The methodology also allows verification of heat, liquid, and vapor fluxes, taking into account the thermal and moisture gradients inside the grain.
V. A. B.
de Oliveira
Universidade Estadual da Paraíba (UEPB), Centro de Ciencias Exatas Sociais Aplicadas
W. C. P. B.
de Lima
Departmento de Engenharia Química, Centro de Ciências e Tecnologia, Universidade Federal de Campina Grande (UFCG), Bodocongó
Severino Rodrigues de Farias
Neto
Departamento de Engenharia Mecânica, Centro de Ciências e Tecnologia, Universidade Federal de Campina Grande (UFCG)
Antonio Gilson Barbosa
de Lima
Departamento de Engenharia Mecânica, Centro de Ciências e Tecnologia, Universidade Federal de Campina Grande (UFCG)
593-605
TORSIONAL OSCILLATIONS OF A DISK IN A CONDUCTING FLUID BOUNDED BY A POROUS MEDIUM UNDER THE EFFECT OF TRANSVERSE MAGNETIC FIELD
The flow due to torsional oscillations of an infinite disk at a small distance from the unbounded porous medium under the effect of a transverse magnetic field has been discussed when the entire space between the disk and the porous medium is filled with a conducting fluid. It is assumed that the flow between the disk and the porous medium is governed by the modified Navier-Stokes equations and that in the porous medium by the modified Brinkman equation. The solution has been obtained by expanding all the entities in the powers of the amplitude of oscillations, which is assumed to be small. It is observed that the axial velocity in the porous medium increases with the increase of the magnetic parameter and decreases with the increase of the Darcy number. The amplitude of the transverse component of velocity decreases with the increase of the magnetic parameter in the entire region.
Parul
Saxena
Department of Mathematics and Astronomy, University of Lucknow, Lucknow, Uttar Pradesh
226007, India
607-614
EFFECTS OF THERMAL RADIATION ON STEADY MHD MIXED CONVECTIVE HEAT TRANSFER FLOW OVER AN IMPERMEABLE INCLINED PLATE EMBEDDED IN A POROUS MEDIUM
This study investigates mixed convection heat transfer about an impermeable inclined plate in the presence of magneto- and thermal radiation effects in a porous medium. The fluid is assumed to be incompressible and dense. The nonlinear coupled parabolic partial differential equations governing the flow are transformed into the non-similar boundary layer equations, which are then solved numerically using the Keller box method. The effects of porosity ε, mixed convection parameter Ri, angle of inclination α, magnetic parameter M, and radiation-conduction parameter Rd on the velocity and temperature profiles as well as on the local skin friction and local heat transfer are presented and analyzed. The validity of the methodology and analysis is checked by comparing the results obtained for some specific cases with those available in the literature.
Orhan
Aydin
Department of Mechanical Engineering, Karadeniz Technical University, 61080 Trabzon, Turkey
Ahmet
Kaya
Department of Mechanical Engineering, Aksaray University
617-625
EFFECT OF TRANSPIRATION ON FREE-CONVECTIVE COUETTE FLOW IN A COMPOSITE CHANNEL
This paper concentrates on the analytical investigation of steady-state convective Couette flow of fluid in a vertical parallel-plate channel partially filled with a porous medium and partially filled with clear fluid in the presence of suction/injection. The Brinkman-extended Darcy model is used to simulate momentum transfer in the porous region. The fluid and porous regions are interlinked by equating the velocity and shear stress jump condition in the case of the momentum equation while matching of the temperature and heat flux have been taken for the thermal energy equation at the interface. Dependence of velocity field, temperature field, mass flow rate, and shear stress on several parameters of the problem is extensively discussed.
Basant K.
Jha
Department of Mathematics, Ahmadu Bello University, Zaria, Nigeria
Josephine Onyema
Odengle
Iya Abubakar Computer Centre, Ahmadu Bello University, Zaria, Nigeria
Muhammad
Kaurangini
Kano University of Science and Technology, Wudil
627-635
MAGNETO AND ROTATORY THERMOSOLUTAL CONVECTION IN COUPLE-STRESS FLUID IN POROUS MEDIUM
The thermosolutal convection in a couple-stress fluid in a porous medium in the presence of uniform rotation and uniform vertical magnetic field (separately) is studied. Using linearized stability theory and normal mode analysis, the dispersion relation is obtained in each case. In the case of magneto thermosolutal convection, the stable solute gradient, magnetic field and couple-stress are found to have stabilizing effects, whereas medium permeability has a destabilizing effect on the system for stationary convection. For rotatory thermosolutal convection, the stable solute gradient and rotation are found to have stabilizing effects, whereas medium permeability and couple-stress have both stabilizing and destabilizing effects for stationary convection. Further, the solute gradient, magnetic field, and rotation are found to introduce oscillatory modes, which were non-existent in their absence. The sufficient conditions for the non-existence of overstability are also obtained.
Mahinder
Singh
Department of Mathematics, Government PG College Seema (Rohru)
Pardeep
Kumar
Department of Mathematics, International Centre for Distance Education and Open Learning (ICDEOL), Himachal Pradesh University, Shimla-171005, India
637-648
NON-DARCY BUOYANCY FLOW IN A SQUARE CAVITY FILLED WITH POROUS MEDIUM FOR VARIOUS TEMPERATURE DIFFERENCE ASPECT RATIOS
A finite element analysis has been carried out to study the influence of a sinusoidally heated bottom wall and linearly heated side walls on natural convection flows in a square cavity filled with a porous medium when the top wall is well insulated. The Darcy-Forchheimer model without the inertia term is used to predict the temperature and flow circulations in the porous medium. In the present study, for a non-uniformly heated bottom wall, the maximum temperature TH was attained at the center of the bottom wall. The side walls were linearly heated, maintaining minimum temperature Tc at the top edges of the side walls and temperature Th at the bottom edges of the side walls; i.e, Tc ≤ Th ≤ TH. The penalty finite-element method with bi-quadratic rectangular elements was used to solve the non-dimensional governing equations for coupled thermal and flow fields. Numerical results are presented for a wide range of parameters of temperature difference aspect ratio A = (Th − Tc)/(TH − Tc)(0 ≤ A ≤ 1) and Darcy number Da (10−5 ≤ Da ≤ 10−3) for higher Rayleigh number Ra = 106 and Prandtl number Pr = 0.7 in terms of stream functions and isotherm contours. Furthermore, the effect of the temperature difference aspect ratio on local and average Nusselt numbers has been analyzed.
M.
Sathiyamoorthy
Department of Mathematics, Government Thirumagal Mills College, Gudiyuatham-632 604, India;Department of Mathematics, SSN College of Engineering, Kalavakkam, Chennai 603110
Tanmay
Basak
Professor
Satyajit
Roy
IIT Madras
649-657