Begell House Inc.
International Journal of Fluid Mechanics Research
FMR
2152-5102
45
4
2018
ON ANALYSIS OF SQUEEZING FLOW BETWEEN ROTATING DISKS WITH CROSS DIFFUSION EFFECTS UNDER THE INFLUENCE OF CORIOLIS AND CENTRIFUGAL FORCES
283-299
Rehan Ali
Shah
Department of Basic Sciences and Islamiat, University of Engineering and Technology
Peshawar, Peshawar, KPK, Pakistan
Aamir
Khan
Department of Basic Sciences and Islamiat, University of Engineering and Technology
Peshawar, Peshawar, KPK, Pakistan
Muhammad
Shuaib
Department of Basic Sciences and Islamiat, University of Engineering and Technology
Peshawar, Peshawar, KPK, Pakistan
Fluid flow may be modeled by a system of differential equations that accounts for the squeezing and rotation effects and
that are coupled with an advection diffusion and energy equation defining the mass and heat flux going from the lower
to the upper disk. This system of equations is characterized by squeezing number S, Prandtl number Pr, Hartmann number M, radiation parameter Rd, Schmidt parameter Sc, Soret number So, suction/injection parameter A, and Dufour number Du. In the case of smooth disks the self-similar equations are solved using the homotopy analysis method (HAM) with appropriate initial guesses and auxiliary parameters to produce an algorithm with an accelerated and assured convergence. The accuracy of the HAM is proved by comparison of the HAM solution with numerical results obtained by BVP4c. A parametric study is tabulated and discussed with graphical aids.
MHD MIXED CONVECTION FLOW OF HEAT-GENERATING/ABSORBING FLUID IN VERTICAL CONCENTRIC ANNULI WITH TIME PERIODIC BOUNDARY CONDITION: STEADY PERIODIC REGIME
301-320
Basant K.
Jha
Department of Mathematics, Ahmadu Bello University, Zaria, Nigeria
Babatunde
Aina
Department of Mathematics, Ahmadu Bello University, Zaria, Nigeria
The effects of heat-generating/absorbing fluid on the flow formation and heat transfer aspects of steady periodic fully
developed mixed convection flow of viscous, incompressible, and electrically conducting fluid in vertical concentric
annuli is studied in the presence of a magnetic field, where the outer surface of the inner cylinder is heated sinusoidally
and the inner surface of the outer cylinder is kept at a constant temperature. The analysis is carried out for fully
developed parallel flow and steady periodic regime. The governing dimensionless momentum and energy equations
are separated into steady and periodic parts and solved analytically. The dimensionless temperature, velocity, pressure
drop, and rate of heat transfer are shown graphically. The effects of dimensionless numbers and pertinent parameters
such as heat generation/absorption, magnetic field, Prandtl number, and the dimensionless frequency on flow fields are
explored. It is discovered that the increase of the heat generation parameter enhanced the rate of heat transfer whereas
an increase of the heat absorption parameter reduced the rate of heat transfer.
MASS TRANSFER EFFECTS ON FLOW THROUGH POROUS MEDIUM PAST AN IMPULSIVELY STARTED INFINITE VERTICAL PLATE IN A ROTATING FLUID
321-338
Ravindra M.
Lahurikar
Goverment College of Arts and Science, Kile Ark, Aurangabad (M.S.) 431001, India
Vinayak T.
Gitte
Nagnathappa Halge, Engineering College Parli Vaijnath, Dist. Beed, India
Pratibha P. Ubale
Patil
Maharashtra Institute of Technology, College, Aurangabad (M.S.) 4310028, India
An exact solution to the unsteady free convection flow of viscous incompressible fluid, in the presence of foreign mass,
through porous medium past an impulsively started infinite vertical isothermal plate in a rotating fluid has been derived
by the Laplace transform technique. Axial and transverse velocity profiles are shown on graphs and numerical values of
skin friction are listed in a table. It is observed that the resistance of the porous medium λ increases as the axial velocity profiles decreases. When air or water is flowing as an infinite medium, the decrease in resistance is greater when λ is large or when the porous medium is more dense. The nondimensional rotational parameter Rc increases when there is
a decrease in the axial velocity profiles for all Prandtl numbers, because the Coriolis forces oppose the fluid flow, and
hence the motion slows down. When Rc < 1, the Coriolis forces are dominated by inertia forces, hence the product of
the nondimensional Rossby number and Reynolds number is large. As Rc < 10−3, the flow field becomes unstable and flow is converted to the turbulent flow for all Prandtl numbers (i.e., Pr = 0.71 for air when Ma « 1 and Pr = 7 for water). The flow of water may become unstable at large values of time t. An increase in the Schmidt number Sc leads to a decrease in axial velocity of both air and water. An increase in the diffusion parameter N leads to a rise in axial velocity because the buoyancy flow forces assist the flow and the transverse skin friction increases for both air and water, while the axial skin friction decreases for air and increases for water. As the permeability parameter λ increases, the axial skin friction increases for both air and water. This happens because more resistance is offered to the flow by porous medium than by a medium that is more dense.
NUMERICAL INVESTIGATION OF EFFECT OF FIBER PROPERTIES ON THROUGH-PLANE PERMEABILITY OF A 3D FIBROUS MEDIUM
339-354
Nikhil Kumar
Palakurthi
Department of Mechanical and Materials Engineering, University of Cincinnati, Cincinnati, Ohio 45221-0072, USA
Santosh Roopak
Dungi
Department of Mechanical and Materials Engineering, University of Cincinnati, Cincinnati, Ohio 45221-0072, USA
Urmila
Ghia
Department of Mechanical and Materials Engineering, University of Cincinnati, Cincinnati, Ohio 45221-0072, USA
Ken
Comer
Procter and Gamble, Cincinnati, Ohio 45201, USA
Darcy permeability is an important parameter that characterizes creeping flow through a fibrous porous medium. It has a complex dependence on the medium's properties, such as porosity and fiber diameter, orientation (in-plane and through-plane), aspect ratio, and curvature. The present study investigates the effect of the aforementioned fiber properties on the through-plane permeability of a fibrous medium. A suite of 3D virtual fibrous structures with a wide range of geometric properties was constructed, and the flow field in the interfiber void space was obtained by solving the 3D incompressible Navier-Stokes equations. For a fixed in-plane and through-plane orientation of the fibers, the permeability was observed to increase as the fiber diameter increases (for a given porosity), and the permeability was found to decrease as the porosity decreases (for a fixed fiber diameter). The numerical results confirmed that the "square of the fiber diameter" is an appropriate normalizing parameter for permeability. For a fixed porosity, the through-plane permeability was found to be independent of the in-plane fiber orientation and increased nonlinearly with an increase in preferential orientation of fibers along the through-plane (flow direction in this study). Also, it was found that the effect of fiber aspect ratio and curvature on permeability was minimal. Finally, the numerical results were used to develop a general expression for through-plane permeability of fibrous media that is applicable for a wide range of porosities and fiber orientations.
EFFECT OF VARIABLE VISCOSITY ON A NANOFLUID OVER A POROUS WEDGE
355-368
Rudra Kanta
Deka
Department of Mathematics, Gauhati University, Guwahati-781014, Assam, India
Mwblib
Basumatary
Department of Mathematics, Lumding College, Lumding-782447, Assam, India
Ashish
Paul
Department of Mathematics, Cotton University, Guwahati-781001, Assam, India
In this paper we have investigated the effects of variable viscosity on a water-based nanofluid over a static porous
wedge with variable temperature. Two different types of nanofluids, copper-water and alumina-water, are considered.
Dual solutions are obtained for negative pressure gradient. The physical aspects of nanofluid flow and heat transfer
characteristics are highlighted and discussed. It is observed that inclusion of nanoparticles and temperature-dependent
viscosity delay the flow separation.
ANALYTICAL SOLUTION OF MHD VISCOUS FLOW OVER A STRETCHING SHEET BY MULTISTAGE OPTIMAL HOMOTOPY ASYMPTOTIC METHOD
369-375
Mehreen
Fiza
Department of Mathematics, Abdul Wali Khan University, Mardan 23200, Pakistan
Saeed
Islam
Department of Mathematics, Abdul Wali Khan University Mardan, 23200 Pakistan
Hakeem
Ullah
Department of Mathematics, Abdul Wali Khan University Mardan, 23200 Pakistan
Farkhanda
Chohan
Department of IT, Burraimi University College, Burraimi, Oman
Qayum
Shah
Department of Basic Sciences and Islamyat, U.E.T. Peshawar, Khyber 25000, Pakistan
In this article, the governing equations of magnetohydrodynamics (MHD) viscous flow over a stretching sheet are reduced to an ordinary boundary value problem using a similarity transformation. The new analytical approach multistep optimal homotopy asymptotic method (MOHAM) is formulated and used for the solution of the boundary value
problem. The comparison of results of MOHAM with the homotopy perturbation method (HPM), exact solution, and numerical results (Runge-Kutta method) revealed that the new technique is a powerful method for solving boundary layer equations. Also, the solution is plotted for various values of β and M.