engIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-357220125217.articleEffects of Thermal Radiation on Hydromagnetic Flow due to a Porous Rotating Disk with Hall EffectS. P. Anjali Devis.p.anjali.devi@jafmonline.net0R. Uma Devir.umadevimaths@gmail.com1Department of Applied Mathematics, Bharathiar University, Coimbatore- 641 046, IndiaDepartment of Mathematics, Bharathiar University, Coimbatore- 641 046, India.Radiation effect on steady laminar hydromagnetic flow of a viscous, Newtonian and electrically conducting fluid past
a porous rotating infinite disk is studied taking Hall current into account. The system of axisymmetric nonlinear
partial differential equations governing the MHD flow and heat transfer are reduced to nonlinear ordinary differential
equations by introducing suitable similarity variables introduced by von Karman and the resulting nonlinear
equations are solved numerically using Runge-Kutta based shooting method. A parametric study of all parameters
involved was conducted and a representative set of results showing the effect of the magnetic field, the radiation
parameter, the uniform suction/injection parameter and Hall parameter are illustrated graphically. The numerical
values of the radial and tangential skin-friction coefficient and Nusselt number are calculated and displayed in the
tables showing the effects of various parameters. Finally, a good comparison between the present numerical
predictions and the previously published data are presented in the absence of magnetic field and radiation.http://jafmonline.net/JournalArchive/download?file_ID=15358&issue_ID=208Rotating disk Hall effect Radiation effect Skinfriction coefficient Nusselt numberengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-3572201252913.articleTransient Approach to Radiative Heat Transfer Free Convection Flow with Ramped Wall TemperatureR. R. Patrar.r.patra@jafmonline.net0S. Dass.das@jafmonline.net1R. N. Janar.n.jana@jafmonline.net2S. K. Ghoshg_swapan2002@yahoo.com3Department of Applied Mathematics,Vidyasagar University, Midnapore 721 102, West Bengal, IndiaDepartment of Applied Mathematics,Vidyasagar University, Midnapore 721 102, West Bengal, IndiaDepartment of Applied Mathematics,Vidyasagar University, Midnapore 721 102, West Bengal, IndiaDepartment of Mathematics, Narajole Raj College,Narajole, Midnapore 721 211, West Bengal, IndiaThe effect of radiation on natural convection incompressible viscous fluid near a vertical flat plate with ramped wall
temperature has been studied. An analytical solution of the governing equation has been obtained by employing
Laplace transform technique. It is examined that two different solutions for the fluid velocities, one valid for fluids of
Prandtl number Pr different from 1 Ra , Ra being the radiation parameter and the other for which the Prandtl
number equal to 1 Ra . The variations of velocities and fluid temperature are presented graphically. Furthermore,
the radiative heat transfer on natural convection flow near a ramped plate temperature has been compared with the
flow near a plate with the constant wall temperature. It is found that an increase in radiation parameter leads to rise
the fluid velocity as well as temperature.http://jafmonline.net/JournalArchive/download?file_ID=15359&issue_ID=208Natural convection Radiation Ramped temperature Isothermal plate and Stefan-Boltzman constantengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-35722012521523.articleExperimental and Numerical Simulation of the Effect of Particles on Flow Structures in Secondary Sedimentation TanksH. Asgharzadehh.asgharzadeh@jafmonline.net0B. Firoozabadifiroozabadi@sharif.edu1H. Afshinh.afshin@jafmonline.net2School of Mechanical Engineering, Sharif university of Technology, Tehran, IranSchool of Mechanical Engineering, Sharif university of Technology, Tehran, IranSchool of Mechanical Engineering, Sharif university of Technology, Tehran, IranSedimentation tanks are designed for removal of floating solids in water flowing through the water treatment plants.
These tanks are one of the most important parts of water treatment plants and their performance directly affects the
functionality of these systems. Flow pattern has an important role in the design and performance improvement of
sedimentation tanks. In this work, an experimental study of particle-laden flow in a rectangular sedimentation tank
has been performed. Kaolin was used as solid particles in these experiments. Also, a numerical simulation was
developed using the finite volume method with a k-ε turbulent model. The results of the numerical model agree well
with the experimental data. Hydrodynamic parameters and flow patterns of the fresh water flow and particle-laden
flow are also compared in this study. The results show that the existence of particles completely changes the flow
structures. It seems that the main reason for this phenomenon is the particles settling. Our experimental observations
and numerical results show that parameters such as the maximum streamwise velocity, fully developed location,
shear stress coefficient at the bottom of the tank and so on are different in water-containing particles compared to
pure water and the inlet concentration strongly intensifies the differences.http://jafmonline.net/JournalArchive/download?file_ID=15360&issue_ID=208Experimental investigation Numerical simulation k-ε turbulent model Rectangular sedimentation tank Particle-laden flowsengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-35722012522531.articleThe Effect of Temperature Dependent Viscosity on MHD Natural Convection Flow from an Isothermal SphereM. M. Mollammamun@gmail.com0S. C. Sahas.c.saha@jafmonline.net1M. A. Hossainm.a.hossain@jafmonline.net2Department of Electrical Engineering & Computer Science, North South University, Dhaka1229, BangladeshSchool of Chemistry, Physics & Mechanical Engineering, Queensland University of Technology, 2 George St., GPO Box 2434, Brisbane QLD 4001, AustraliaDepartment of Mathematic, COMSATS Institute of Information Technology, Islamabad, PakistanLaminar magnetohydrodynamic (MHD) natural convection flow from an isothermal sphere immersed in a fluid with
viscosity proportional to linear function of temperature has been studied. The governing boundary layer equations are
transformed into a non-dimensional form and the resulting nonlinear system of partial differential equations are
reduced to convenient form which are solved numerically by two very efficient methods, namely, (i) Implicit finite
difference method together with Keller box scheme and (ii) Direct numerical scheme. Numerical results are presented
by velocity and temperature distribution, streamlines and isotherms of the fluid as well as heat transfer characteristics,
namely the local skin-friction coefficients and the local heat transfer rate for a wide range of magnetohydrodynamic
paramagnet and viscosity-variation parameter.http://jafmonline.net/JournalArchive/download?file_ID=15361&issue_ID=208Natural convection MHD Temperature dependent viscosity Finite difference SphereengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-35722012523342.articleInfluence of Heat Input, Working Fluid and Evacuation Level on the Performance of Pulsating Heat PipeK. Rama Narasimhak.ramanarasimha@gmail.com0S. N. Sridharas.n.sridhara@jafmonline.net1M. S. Rajagopalm.s.rajagopal@jafmonline.net2K. N. Seetharamuk.n.seetharamu@jafmonline.net3Centre for Emerging Technologies, Jain University, Bangalore, Karnataka, 562112, IndiaK.S. School of Engineering and Management, Bangalore, Karnataka, 560062, IndiaGlobal Academy of Technology, Bangalore, Karnataka, 560098, IndiaP.E.S. Institute of Technology, Bangalore, Karnataka, 560085, IndiaAn experimental study on pulsating heat pipe (PHP) is presented in this work. A closed loop PHP with a single U
turn is fabricated and tested. The transient and steady state experiments are conducted and operating temperatures are
measured. The experiments are carried out for different working fluids, heat input and for different evacuation levels.
The derived parameters include thermal resistance and heat transfer coefficient of PHP. The results of these
experiments show an intermittent motion of the working fluid at lower heat input. The temperature difference
between evaporator and condenser at steady state is found lower for acetone compared to water, ethanol and
methanol. Lower value of thermal resistance and higher value of heat transfer coefficient are observed in case of
acetone compared to water, ethanol and methanol. Lower values of temperature difference between evaporator and
condenser and thermal resistance and higher value of heat transfer coefficient are observed at atmospheric conditions
of operation of PHP compared to evacuation conditions. The Power Spectral Density Analysis is also carried out on
the results of these experiments using FFT technique to analyse the pulsating motion of the fluid in a PHP. In the
Power Spectral Density analysis, the frequency distribution of temperature variation in PHP was observed over a
wider range, signifying the periodic motion in the fluid flow of the liquid slug and vapour plug. This characteristic
frequency corresponded to the characteristic time for a couple of adjacent vapour plug and liquid slug passing
through a specific local wall surface in a PHP.http://jafmonline.net/JournalArchive/download?file_ID=15362&issue_ID=208Pulsating heat pipe Electronic Cabinet cooling FFT analysisengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-35722012524353.articleBuoyancy Driven Heat Transfer in Cavities Subjected to Thermal Boundary Conditions at Bottom Wall Aswathaaswath_bit@yahoo.co.in0C. J. Gangadhara Gowdac.j.gangadharagowda@jafmonline.net1S. N. Sridharas.n.sridhara@jafmonline.net2K. N. Seetharamuk.n.seetharamu@jafmonline.net3Department of Mechanical Engineering, Bangalore Institute of Technology, Bangalore, Karnataka, 560 004, INDIADepartment of Mechanical Engineering, PES College of Engineering, Mandya - 571 401, INDIARotary Machinery Division, M. S. Ramaiah School of Advanced Studies, Bangalore - 560 054, INDIADepartment of Mechanical Engineering, PES Institute of Technology, Bangalore - 560 085, INDIANatural convection in cavities is studied numerically using a finite volume based computational procedure. The
enclosure used for flow and heat transfer analysis has been bounded by adiabatic top wall, constant temperature cold
vertical walls and a horizontal bottom wall. The bottom wall is subjected to uniform/sinusoidal/linearly varying
temperatures. Nusselt numbers are computed for Rayleigh numbers (Ra) ranging from 103 to 107 and aspect ratios
(H/L) 0.5 and 1. Air is taken as working fluid (Pr = 0.7). Results are presented in the form of stream lines, isotherm
plots and average Nusselt numbers. It is observed from this study that the uniform temperature at the bottom wall
gives higher Nusselt number compared to the sinusoidal and linearly varying temperature cases. The average Nusselt
number increases monotonically with Rayleigh number for both aspect ratio 1 and 0.5 for bottom wall and side walls.
For the case of aspect ratio 1, the average Nusselt number for a given Rayleigh number increases at the bottom wall
compared to aspect ratio 0.5. However, the average Nusselt number increases as the aspect ratio decreases from 1 to
0.5 for side wall except for uniform temperature case.http://jafmonline.net/JournalArchive/download?file_ID=15363&issue_ID=208Natural convection Cavities Aspect ratio Thermal boundary conditions Numerical heat transferengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-35722012525565.articleOn the Effects of Rotation on the Passive Scalar and Kinematic Fields of Homogeneous Sheared TurbulenceB. Chebbib.chebbi@jafmonline.net0M. Bouzaianembouzaiane@yahoo.fr1Laboratoire de mécanique des fluides, Département de Physique, Faculté des Sciences de TunisLaboratoire de mécanique des fluides, Département de Physique, Faculté des Sciences de TunisIn this work, the effect of rotation on the evolution of kinematic and passive scalar fields in two dimensional
homogeneous sheared turbulence is studied using two different approaches. The first one is analytical and it consists
on the resolution of differential linear equations governing the turbulence at high shear when the non linear effects
are neglected. The second one is numerical and it consists on the modeling of governing equations using the most
known second order models of turbulence and their numerical integration using the fourth order Runge-kutta method.
In this second approach, the classic Launder Reece Rodi model, the Speziale Sarkar Gatski and the Shih Lumley
models are retained for the pressure-strain correlation, pressure-scalar gradient correlation and for the time evolution
equations of the kinematic and scalar dissipations. The evolution of turbulence is studied according to the
dimensionless rotation number R which is varied from -0.75 to 0.5. The obtained results are compared to the recent
results of the DNS of Brethouwer. Both methods have confirmed the existence of asymptotic equilibrium states for
dimensionless kinematic and scalar parameters.http://jafmonline.net/JournalArchive/download?file_ID=15364&issue_ID=208Turbulence with the rotation Passive scalar field Second order modeling Asymptotic behaviorengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-35722012526774.articleEffects of Hall Current and Rotation on Unsteady MHD Couette Flow in the Presence of an Inclined Magnetic FieldG. S. Sethgsseth_ism@yahoo.com0R. Nandkeolyarr.nandkeolyar@jafmonline.net1Md. S. Ansarimd.s.ansari@jafmonline.net2Department of Applied Mathematics, Indian School of Mines, Dhanbad-826004, IndiaSchool of Applied Sciences, KIIT University, Bhubaneswar-751024, IndiaSchool of Petroleum Technology, Pandit Deendayal Petroleum University, Gandhinagar-382007, IndiaUnsteady hydromagnetic Couette flow of a viscous incompressible electrically conducting fluid in a rotating system
in the presence of an inclined magnetic field taking Hall current into account is studied. Fluid flow within the channel
is induced due to impulsive movement of the lower plate of the channel. Exact solution of the governing equations is
obtained by Laplace transform technique. The expression for the shear stress at the moving plate is also derived.
Asymptotic behavior of the solution is analyzed for small and large values of time t to highlight (i) the transient
approach to the final steady state flow and (ii) the effects of Hall current, magnetic field, rotation and angle of
inclination of magnetic field on the flow-field. It is found that Hall current and rotation tend to accelerate fluid
velocity in both the primary and secondary flow directions. Magnetic field has retarding influence on the fluid
velocity in both the primary and secondary flow directions. Angle of inclination of magnetic field has accelerating
influence on the fluid velocity in both the primary and secondary flow directions.http://jafmonline.net/JournalArchive/download?file_ID=15365&issue_ID=208MHD Couette flow Hall current Inclined magnetic field Modified Ekman-Hartmann boundary layer Rayleigh boundary layer Spatial and inertial oscillationsengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-35722012527583.articleDynamic Analysis of Small Pig through Two and Three- Dimensional Liquid PipelineM. Lesanim.lesani@jafmonline.net0M. Rafeeyanrafeeyan@yazd.ac.ir1A. Sohankara.sohankar@jafmonline.net2Department of Mechanical Engineering, Yazd University, Yazd, IRANDepartment of Mechanical Engineering, Yazd University, Yazd, IRANDepartment of Mechanical Engineering, Yazd University, Yazd, IRANThe derivation and solution of the two and three dimensional dynamic equations for a small pipeline inspection
gauge (Pig) through a liquid pipeline is the main aim of this work. These equations can be used for synthesis of speed
controller of a pig by using a bypass port in Pig. Momentum and energy equations are employed to study the
influence of flow field on the Pig’s trajectory. The pig is assumed to be a small rigid body with a bypass hole in its
body. The variation of the diameter of the bypass port, which is controlled by a valve, is considered in this
formulation. The path of the pig or geometry of the pipeline is assumed to be 2D and 3D curve. 2D and 3D
simulations of the pig motion are performed individually and a case has been solved and discussed for each of them.
The simulation results show that the derived equations are valid and effective for online estimating of the position,
velocity and forces acting on the pig at any time of its motion.http://jafmonline.net/JournalArchive/download?file_ID=15366&issue_ID=208Pig Dynamic equations Liquid pipeline Momentum and energy equationsengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-35722012528598.articleThermodynamics of Energy Systems and Processes: A Review and PerspectivesM. Feidtmichel.feidt@ensem.inpl-nancy.fr0Université Henri Poincaré, LEMTA – ENSEM 2, avenue de la Forêt de Haye, Vandoeuvre-les-Nancy, 54516, FranceThermodynamics is a relatively recent physical science that was born with calorimetry and thermometry experiments:
so heat remains the central concept in relation with other forms of energy. The coupling between various forms is
essential and related to conversion processes. The first conversion process that was analyzed was the
thermomechanical one, at the time of Carnot. Equilibrium Thermodynamics was fruitful in connection with the
efficiency concept, to qualify engines. But since that time, mass and heat transfers studies have been strongly
developed (thermokinetics), as well as second law aspects of thermodynamics. It results new appraisal for energy
systems and processes, relevant of a true thermodynamics approach. This was initiated by Onsager at the beginning
of the 20th century, by analyzing the relation between fluxes and forces (gradients) from a general, but linear point of
view. More recently, it was developed through a lumped analysis for systems by Chambadal and Novikov in 1957. It
was rediscovered in 1975, by Curzon and Ahlborn. And since this work, a lot of books and publications have been
proposed in the literature. A review of them is proposed here, on the basis of a synthesis due to the lack of place. The
author’s works are analysed and compared to the literature too. It results some original remarks and proposal relative
to the obtained results: Comparison of entropy ratio method to entropy flux method, Comparison of endoreversible
case to irreversible case, Comparison of adiabatic and non adiabatic systems, Comparison of constrained and non
constrained systems. Main consequences of these comparisons are given, and future perspectives evoked on the main
systems categories (engines; reverse machines; other eventual configurations).Conclusion is that FDOT (Finite
Dimensions Thermodynamics) appears as a promising tool to be enlarged in the future.http://jafmonline.net/JournalArchive/download?file_ID=15368&issue_ID=208Energy systems and processes Thermodynamics OptimizationengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-357220125299112.articleSome Insight into the Wind-Induced Vibration of Stay Cables in the Context of Rigid Static Inclined Circular CylinderA. Raeesiraeesi@uwindsor.ca0S. Chengs.cheng@jafmonline.net1D. S-K Tingd.s.k.ting@unspecified.net2Department of Civil and Environmental Engineering, University of WindsorDepartment of Civil and Environmental Engineering, University of WindsorDepartment of Mechanical, Automotive and Materials Engineering, University of Windsor 401 Sunset Ave., Windsor, ON., Canada N9B 3PWind-induced cable vibration is a contemporary issue in cable-stayed bridges, which potentially threats the safety
and durability of the structure. A thorough understanding of the fundamental physics underlying these phenomena is
a priori for developing effective remedies to resolve the issue. In the present paper, possible mechanisms associated
with two different types of wind-induced cable vibration phenomena have been studied based on a set of wind tunnel
experimental data on a rigid circular cylinder. A number of analyses were applied to the unsteady surface pressure
data sampled on the cylinder model to elucidate the possible mechanisms of these phenomena. Negative aerodynamic
damping ratios were identified in the ranges of Reynolds number and cylinder orientation where divergent galloping
type of response is expected to occur. A breakdown range of wind-cable relative angle was detected in which the
regular Karman vortex shedding was suppressed within the subcritical Reynolds number range. In the critical
Reynolds number range, however, the symmetry of surrounding flow field beyond this breakdown range could be
altered drastically, leading to considerable changes in the lift force which is responsible for the negative aerodynamic
damping ratio values. Significant increase of correlation length of sectional aerodynamic forces was also detected
within this breakdown range in the critical regime. This, combined with the negative aerodynamic damping, is
proposed to be a possible necessary onset condition for the galloping of dry inclined cables. The limited-amplitude
instability, which occurred in the subcritical Re range, on the other hand, was found to be caused by the mitigation of
regular Karman vortex shedding in the breakdown range while the spatial flow field was strongly correlated. In
addition, the decay in correlation of aerodynamic forces in the critical Re range was believed to be key to the
suppression of this unstable response.http://jafmonline.net/JournalArchive/download?file_ID=15369&issue_ID=208Circular cylinder; Dry inclined cable galloping; Critical Reynolds number regime; Spatial correlation; Aerodynamic damping; High-speed vortex excitationengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-3572201252113121.articleCombined Effects of Thermal Radiation and Hall Current on MHD Free-Convective Flow and Mass Transfer over a Stretching Sheet with Variable ViscosityG. C. Shitgcs@math.jdvu.ac.in0R. Haldarr.haldar@jafmonline.net1Department of Mathematics, Jadavpur University, Kolkata-700032, IndiaDepartment of Mathematics, Jadavpur University, Kolkata-700032, IndiaAn analysis has been carried out on the effects of thermal radiation and Hall current of a magneto hydrodynamic freeconvective
flow and mass transfer over a stretching sheet with variable viscosity in the presence of heat
generation/absorption. The fluid viscosity is assumed to vary as an inverse linear function of temperature. The
boundary-layer equations governing the flow problem under consideration have been reduced to a system of nonlinear
ordinary differential equations by employing a similarity transformation. Using the finite difference scheme,
numerical solutions to the transform ordinary differential equations have been obtained and the results are presented
graphically. The numerical results obtained are in good agreement with the existing scientific literature.http://jafmonline.net/JournalArchive/download?file_ID=15370&issue_ID=208Thermal radiation; Variable viscosity; MHD; Hall current; Heat and Mass transferengIsfahan University of TechnologyJournal of Applied Fluid Mechanics1735-3572201252123132.articleHigh Performance Computing of Three-Dimensional Finite Element Codes on a 64-bit MachineM. P. Rajuraju192@gmail.com0S. K. Khaitans.k.khaitan@jafmonline.net1Department of Mechanical Engg., Case Western Reserve University, Cleveland, OH, 44106, USADepartment of Electrical Engg., Iowa State University, Ames, IA, 50014, USAThree dimensional Navier-Stokes finite element formulations require huge computational power in terms of memory
and CPU time. Recent developments in sparse direct solvers have significantly reduced the memory and
computational time of direct solution methods. The objective of this study is twofold. First is to evaluate the
performance of various state-of-the-art sequential sparse direct solvers in the context of finite element formulation of
fluid flow problems. Second is to examine the merit in upgrading from 32 bit machine to a 64 bit machine with larger
RAM capacity in terms of its capacity to solve larger problems. The choice of a direct solver is dependent on its
computational time and its in-core memory requirements. Here four different solvers, UMFPACK, MUMPS,
HSL_MA78 and PARDISO are compared. The performances of these solvers with respect to the computational time
and memory requirements on a 64-bit windows server machine with 16GB RAM is evaluated.http://jafmonline.net/JournalArchive/download?file_ID=15371&issue_ID=208Multifrontal UMFPACK MUMPS HSL MA78 PARDISO 64-bit