Begell House
Journal of Porous Media
Journal of Porous Media
1091-028X
19
5
2016
FLOW AND HEAT TRANSFER IN A SEMIPOROUS CURVED CHANNEL WITH RADIATION AND POROSITY EFFECTS
In the present analysis flow and heat transfer of a viscous fluid in a semiporous curved channel coiled in a circle of radius R through a Darcy porous medium with convective boundary condition is discussed. In addition, the effects of thermal radiation are also considered. The mathematical model of the flow and heat transfer problem is developed by using a curvilinear coordinate system. Similar solutions are computed numerically by a shooting method. The results are also validated with the well-known finite difference technique known as the Keller-Box method. Fluid velocity, temperature, skin friction coefficient, and rate of heat transfer at the wall are discussed through graphs and tables for the various values of the involved parameters.
Muhammad
Naveed
Department of Mathematics, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan
Zaheer
Abbas
Department of Mathematics, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan
Muhammad
Sajid
Department of Mathematics and Statistics, International Islamic University, Islamabad 44000, Pakistan
379-389
STABILITY OF COUPLE STRESS FLUID FLOW THROUGH A HORIZONTAL POROUS LAYER
The stability of pressure-driven parallel shear flow in a horizontal layer of couple stress fluid saturated porous medium is investigated using a classical linear stability theory. A modified Orr-Sommerfeld equation is derived and solved numerically using the Chebyshev collocation method. The critical Reynolds number, the critical wave number, and the critical wave speed are computed for various values of the porous and couple stress parameters. The equilibrium is always stable if the convective inertial term is omitted, but with its inclusion the basic state becomes unstable depending on the choices of physical parameters. It is found that an increase in the couple stress parameter has a destabilizing effect on the fluid flow, while an opposite trend is observed with increasing porous parameter. The streamlines presented herein demonstrate the development of complex dynamics at the critical state. Individual components of the kinetic energy spectrum are analyzed and presented for different parametric values in order to obtain detailed information at the critical state of fluid flow.
B. M.
Shankar
Department of Mathematics, PES University, Bangalore 560 085, India
I. S.
Shivakumara
Department of Mathematics, Bangalore University, Bangalore 560 056, India
Chiu-On
Ng
Department of Mechanical Engineering, The University of Hong Kong, Pokfulam, Hong Kong, People's Republic of China
391-404
IMPROVEMENT OF PERMEABILITY MODELS USING LARGE MERCURY INJECTION CAPILLARY PRESSURE DATASET FOR MIDDLE EAST CARBONATE RESERVOIRS
In this study, eight permeability models are calibrated to a large mercury injection capillary pressure dataset obtained from the Middle East region. The permeability models are: Purcell, Thomeer, Winland, Swanson, Pittman, Huet, Dastidar, in addition to the Buiting-Clerke permeability models. The coefficients of the models have been determined using three different regression techniques: ordinary nonlinear least-squares regression, weighted nonlinear regression, and multiple regressions of nonlinear models after linearization. Using the original and adjusted coefficients, permeability values were estimated and compared to the actual data. Comprehensive statistical and graphical comparison is made between the different regression techniques. The study indicates that, in general, permeability models with published constants produce high errors. Major improvements in results, however, have been accomplished when using the generalized permeability models with their calibrated coefficients. The modified Winland and Swanson models show the best prediction performance. In addition, the modified Purcell model shows a significant improvement with the updated parameters. This study enhances the estimation of absolute permeability and hence better reservoir description.
Hasan A.
Nooruddin
Saudi Aramco, Dhahran, Saudi Arabia
M. Enamul
Hossain
King Fahd University of Petroleum & Minerals (KFUPM), Dhahran, Saudi Arabia; Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
Hasan
Al-Yousef
King Fahd University of Petroleum & Minerals (KFUPM), Dhahran, Saudi Arabia
Taha
Okasha
Saudi Aramco, Dhahran, Saudi Arabia
405-422
IRREVERSIBILITY ANALYSIS OF VARIABLE THERMAL CONDUCTIVITY MHD RADIATIVE FLOW IN A POROUS CHANNEL WITH DIFFERENT NANOPARTICLES
The entropy generation on radiative heat transfer performance in the flow of variable thermal conductivity, optically thin viscous water-based nanofluid with an external magnetic field through a porous parallel channel is investigated in the present work. Three types of nanoparticles, Cu, TiO2, and Al2O3, are used to observe their performance. The fluid temperature in the channel varies due to the asymmetric heating of the walls as well as viscous dissipation. Our approach uses the power series from the governing nonlinear differential equations for small values of the thermal conductivity variation parameter which are then analyzed by various generalizations of the Hermite- Pade approximation method. The influences of the pertinent governing flow parameters on velocity, temperature, thermal conductivity criticality conditions, and entropy generation are discussed extensively, both numerically and graphically. A stability analysis has been performed for the local rate of heat transfer, which signifies that the lower solution branch is stable and physically acceptable whereas the upper solution branch is unstable. It is interesting to note that the entropy generation of the system increases at the two porous plates as well as that the fluid friction irreversibility is dominant there.
Md. S.
Alam
Department of Mathematics, Jagannath University, Dhaka-1100, Bangladesh
Md. Abdul Hakim
Khan
Department of Mathematics, Bangladesh University of Engineering and Technology, Dhaka-1000, Bangladesh
Md. Abdul
Alim
Department of Mathematics, Bangladesh University of Engineering and Technology, Dhaka-1000, Bangladesh
423-439
THERMAL PERFORMANCE AND EMISSION CHARACTERISTICS OF NEWLY DEVELOPED POROUS RADIANT BURNER FOR COOKING APPLICATIONS
This paper presents the characteristics, thermal performance, and emission performance of conventional burners (CB) and a new porous radiant burner (PRB). The PRB was designed and fabricated with the purpose of improving the thermal performance of the existing self-aspirated cooking burners and to maintain the emissions within acceptable limits. The PRB was trilayered and consisted of a ceramic matrix made from a ceramic base, stainless steel balls, and a mild steel plate. The outer cover of the burner was cylindrical in structure and made up of mild steel so that it could be easily adaptable to normal cooking stoves. The maximum thermal efficiency was improved by 7% compared to CB under similar experimental conditions. Also, it was observed that the emission values were well within the WHO standards. A uniform surface temperature distribution was achieved for the PRB compared to CB used in this work. Use of a sophisticated design and fabrication process might further improve the performance of the burner.
Premananda
Pradhan
School of Mechanical Engineering, KIIT University, Bhubaneswar-751024, Odisha, India
Purna Chandra
Mishra
School of Mechanical Engineering, KIIT University, Bhubaneswar-751024, Odisha, India
Kunja Bihari
Sahu
School of Mechanical Engineering, KIIT University, Bhubaneswar-751024, Odisha, India
441-452
LATTICE-BOLTZMANN ANALYSIS OF CAPILLARY RISE
The current study presents an investigation of capillary flow by using the two-phase lattice-Boltzmann method. The Shan-Chen single-component multiphase model was applied to simulate capillary rise in straight and sinusoidal capillaries. In order to validate our code, three test cases are considered: (a) The Laplace law is tested for various droplets, (b) the contact angle was verified by comparing the ratio of droplet wet length to droplet height at various adhesion parameters and (c) the verification of the Washburn equation for long times. The density distribution was presented for different geometry configurations and liquid front position was plotted as a function of time. The numerical results showed that the Washburn equation is not valid for short times. The internal structure of the flow inside the capillaries was described, thus the analysis shows the forming of recirculation zones near the inlet region and a decelerating effect of the varying path on the meniscus movement. For sinusoidal capillaries, we notice that the meniscus reaches different equilibrium positions.
Mohamed El Amine
Ben Amara
Laboratoire d'Etudes des Systemes Thermiques et Energetiques, Ecole Nationale d'Ingenieurs de Monastir, Monastir 5019, Tunisia
Patrick
Perre
Laboratoire de Genie des Procedes et des Materiaux, Ecole Centrale Paris, CentraleSupelec, campus de Chatenay-Malabry Grande Voie des Vignes F-92 295 Chatenay-Malabry Cedex, Paris, France
Sassi Ben
Nasrallah
Energy and Thermal Systems Laboratory, National Engineering School of Monastir, University of Monastir, Avenue Ibn El Jazzar, 5019 Monastir, Tunisia
453-469