scholarly journals Induced magnetic field and viscous dissipation on flows of two immiscible fluids in a rectangular channel

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Nehad Ali Shah ◽  
Hussam Alrabaiah ◽  
Dumitru Vieru ◽  
Se-Jin Yook
Keyword(s):  
Magnetic Field ◽  
Viscous Dissipation ◽  
Fluid Velocity ◽  
Rectangular Channel ◽  
Immiscible Fluids ◽  
Temperature Fields ◽  
Induced Magnetic Field ◽  
Transform Method ◽  
Approximate Analytical Solutions ◽  
The Laplace Transform

AbstractThe unsteady, magneto-hydrodynamic generalized Couette flows of two immiscible fluids in a rectangular channel with isothermal walls under the influence of an inclined magnetic field and an axial electric field have been investigated. Both fluids are considered electrically conducting and the solid boundaries are electrically insulated. Approximate analytical solutions for the velocity, induced magnetic, and temperature fields have been determined using the Laplace transform method along with the numerical Stehfest's algorithm for the inversion of the Laplace transforms. Also, for the nonlinear differential equation of energy, a numerical scheme based on the finite differences has been developed. A particular case has been numerically and graphically studied to show the evolution of the fluid velocity, induced magnetic field, and viscous dissipation in both flow regions.

Approximate Analytical Solutions for Marangoni Mixed Convection Boundary Layer

2010 ◽  
Author(s):  
Yan Zhang ◽  
Liancun Zheng ◽  
Jiemin Liu
Keyword(s):  
Boundary Layer ◽  
Mixed Convection ◽  
Analytical Solutions ◽  
External Pressure ◽  
Immiscible Fluids ◽  
Temperature Fields ◽  
Convection Boundary Layer ◽  
Coupling Condition ◽  
Approximate Analytical Solutions ◽  
Convection Boundary

The paper deals with a steady coupled dissipative layer, called Marangoni mixed convection boundary layer, which can be formed along the interface of two immiscible fluids, in surface driven flows. The mixed convection boundary layer is generated besides the Marangoni convection effects induced flow over the surface due to an imposed temperature gradient, there are also buoyancy effects due to gravity and external pressure gradient effects. We shall use a model proposed by Chamkha wherein the Marangoni coupling condition has been included into the boundary conditions at the interface. The similarity equations are first determined, and the approximate analytical solutions are obtained by an efficient transformation, asymptotic expansion and Pade´ approximant technique. The features of the flow and temperature fields as well as the interface velocity and heat transfer at the interface are discussed for some values of the governing parameters. The associated fluid mechanics was analyzed in detail.

Magnetohydrodynamic Mixed Convective Flow Due to a Vertical Plate With Induced Magnetic Field

2018 ◽  
Vol 10 (6) ◽  
Author(s):  
R. Nandkeolyar ◽  
M. Narayana ◽  
S. S. Motsa ◽  
P. Sibanda
Keyword(s):  
Magnetic Field ◽  
Partial Differential Equations ◽  
Differential Equations ◽  
Fluid Velocity ◽  
Nonlinear Partial Differential Equations ◽  
Linearization Method ◽  
Fluid Temperature ◽  
Magnetic Field Effects ◽  
Induced Magnetic Field ◽  
Partial Differential

The steady hydromagnetic flow of a viscous, incompressible, perfectly conducting, and heat absorbing fluid past a vertical flat plate under the influence of an aligned magnetic field is studied. The flow is subject to mixed convective heat transfer. The fluid is assumed to have a reasonably high magnetic Prandtl number which causes significant-induced magnetic field effects. Such fluid flows find application in many magnetohydrodynamic devices including MHD power-generation. The effects of viscous dissipation and heat absorption by the fluid are investigated. The governing nonlinear partial differential equations are converted into a set of nonsimilar partial differential equations which are then solved using a spectral quasi-linearization method (SQLM). The effects of the important parameters on the fluid velocity, induced magnetic field, fluid temperature and as well as on the coefficient of skin-friction and the Nusselt number are discussed qualitatively.

MHD flow and heat transfer of a magnetite–water nanofluid in porous medium under the effects of chemical reaction

2017 ◽  
Vol 14 (3) ◽  
pp. 193-199 ◽  
Author(s):  
Meysam Amini ◽  
Esmaeil GhasemiKafrudi ◽  
Mohammad Reza Habibi ◽  
Azin Ahmadi ◽  
Akram HosseinNia
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Chemical Reaction ◽  
Fluid Velocity ◽  
Mhd Flow ◽  
Industrial Applications ◽  
Temperature Fields ◽  
Stagnation Flow ◽  
Content Type ◽  
Flow And Heat Transfer

Purpose Due to the extensive industrial applications of stagnation flow problems, the present work aims to investigate the magnetohydrodynamics (MHD) flow and heat transfer of a magnetite nanofluid (here Fe3O4–water nanofluid) impinging a flat porous plate under the effects of a non-uniform magnetic field and chemical reaction with variable reaction rate. Design/methodology/approach Similarity transformations are applied to reduce the governing partial differential equations with boundary conditions into a system of ordinary differential equations over a semi-infinite domain. The modified fourth-order Runge–Kutta method with the shooting technique which is developed for unbounded domains is conducted to give approximate solutions of the problem, which are then verified by results of other researchers, showing very good agreements. Findings The effects of the volume fraction of nanoparticles, permeability, magnetic field, chemical reaction and Schmidt number on velocity, temperature and concentration fields are examined and graphically illustrated. It was found that fluid velocity and temperature fields are affected strongly by the types of nanoparticles. Moreover, magnetic field and radiation have strong effects on velocity and temperature fields, fluid velocity increases and thickness of the velocity boundary layer decreases as magnetic parameter M increases. The results also showed that the thickness of the concentration boundary layer decreases with an increase in the Schmidt number, as well as an increase in the chemical reaction coefficient. Research limitations/implications The thermophysical properties of the magnetite nanofluid (Fe3O4–water nanofluid) in different conditions should be checked. Practical implications Stagnation flow of viscous fluid is important due to its vast industrial applications, such as the flows over the tips of rockets, aircrafts, submarines and oil ships. Moreover, nanofluid, a liquid containing a dispersion of sub-micronic solid particles (nanoparticles) with typical length of the order of 1-50 nm, showed abnormal convective heat transfer enhancement, which is remarkable. Originality/value The major novelty of the present work corresponds to utilization of a magnetite nanofluid (Fe3O4–water nanofluid) in a stagnation flow influenced by chemical reaction and magnetic field. It should be noted that in addition to a variable chemical reaction, the permeability is non-uniform, while the imposed magnetic field also varies along the sheet. These, all, make the present work rather original.

scholarly journals An electromagnetic arrayed pump to create arbitrary velocity profiles in fluid

2021 ◽  
Vol 3 (12) ◽  
Author(s):  
Seyed Peyman Hashemi ◽  
Mohammad Reza Karafi ◽  
Mohammad Hossein Sadeghi ◽  
Vahid Rezaei Esfedan
Keyword(s):  
Magnetic Field ◽  
Fluid Velocity ◽  
Rectangular Channel ◽  
Velocity Profiles ◽  
List Type ◽  
Finite Element Software ◽  
Electromagnetic Pump ◽  
Naoh Solution ◽  
Arbitrary Velocity ◽  
The Magnetic Field

AbstractThe present paper is conducted to develop a new structure of an electromagnetic pump capable of controlling the magnetic field in a rectangular channel. Common electromagnetic pumps do not create uniform velocity profiles in the cross-section of the channel. In these pumps, an M-shape profile is created since the fluid velocity in the vicinity of the walls is higher than that in its center. Herein, the arbitrary velocity profiles in the electromagnetic pump are generated by introducing an arrayed structure of the coils in the electromagnetic pump and implementing 3D numerical simulation in the finite element software COMSOL. The dimensions of the rectangular channel are 5.5 × 150 mm2. Moreover, the magnetic field is provided using a core with an arrayed structure made of low-carbon iron, as well as five couples of coils. 20% NaoH solution is utilized as the fluid (conductivity: 40 S/m). The arrayed pump is fabricated and experimentally created an arbitrary velocity profile. The pressure of the pump in every single array is 12 Pa and the flow rate is equal to 3375 mm3/s. According to the results, there is a good agreement between the experimental test carried out herein and the simulated models.Article highlights This is the first time that the idea of arrayed electromagnetic pump is presented. This pump uses a special arrayed core with coils; by controlling the current of each coil and the direction of the currents, the magnetic field under the core could be adjusted. By changing the magnetic field at any position in the width of the channel, the Lorentz force alters, which leads to different velocity and pressure profiles. Using COMSOL multiphysics software, the electromagnetic pump was simulated in real size compared to the experimental model. Subsequently, the simulation model was verified and different velocity profiles were generated by activation and deactivation of different coils. The pressure and velocity curves and contours were extracted. The experimental setup was manufactured and assembled. NaOH solution was utilized as the fluid. Afterwards, different modes of coil activations were investigated and the pressure and velocity profiles of the pump were calculated.

Thermo-diffusion impacts on the flow of an elastico-viscous fluid over an inclined heated plane with magnetized wall

2021 ◽  
pp. 095440892110692
Author(s):  
Jitendra Kumar Singh ◽  
Gauri Shenker Seth
Keyword(s):  
Magnetic Field ◽  
Viscous Fluid ◽  
Fluid Velocity ◽  
Surface Current ◽  
Induced Magnetic Field ◽  
Regular Perturbation ◽  
Surface Current Density ◽  
Magnetic Diffusion ◽  
Mass Fluxes ◽  
Flow Surface

The focus is in this article is to scrutinize the simultaneous significances of magnetic diffusion, thermo-diffusion and angular location on the hydromagnetic flow of an elastico-viscous fluid over an inclined heated plane with magnetized wall. The flow medium is considered to be uniformly permeable (Darcy-Brinkman porous medium) and the flow of the fluid is considerably affected due to the appearance of a strong magnetic field in the direction normal to the flow surface. The significances of Hall current, induced magnetic field and Coriolis force on flow nature is also included in the study. The leading non-dimensionalized equations are explored by regular perturbation analysis. Ultimately, the expressions for velocity field, induced magnetic field, temperature and concentration are obtained. We further derived the surface skin friction, surface current density, heat and mass fluxes. The computation of results is performed with the aid of Mathematica software and results are presented in graphical and tabular forms for distinct flow impacting parameters. Numerical simulation explores that mass diffusion factor brings growth in the fluid velocity, temperature and normal induced magnetic field while it reduces the main induced magnetic field. Magnetic diffusion develops the primary flow and primary induced magnetic field and lessens the normal flow and normal induced magnetic field. Inclination angle of the heated plane upgrades primary induced magnetic field while downgrading normal induced magnetic field.

Unsteady Hydromagnetic Boundary Layer in a Rotating Medium

1976 ◽  
Vol 43 (2) ◽  
pp. 205-208 ◽  
Author(s):  
P. Puri ◽  
P. K. Kulshrestha
Keyword(s):  
Magnetic Field ◽  
Porous Plate ◽  
Three Dimensional ◽  
Power Input ◽  
Transverse Magnetic ◽  
Laplace Transform Method ◽  
Transform Method ◽  
Rotating Medium ◽  
The Laplace Transform ◽  
The Magnetic Field

The three-dimensional flow of a viscous fluid in the presence of the transverse magnetic field past an infinite porous plate moving with a time-dependent velocity in a rotating medium is investigated. An exact solution is found by using the Laplace transform method. The order of Stokes, Ekman, and Stokes-Rayleigh layers arising in the problem are derived and the influence of the magnetic field and suction (blowing) is studied. The behavior of the drag and lateral stress on the plate is discussed and the power input required to keep the plate in motion calculated. It is also found that a normal solution exists at the resonant frequency for the problem investigated here.

Reverse Flow in Magnetoconvection of Two Immiscible Fluids in a Vertical Channel

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Alessandra Borrelli ◽  
Giulia Giantesio ◽  
Maria Cristina Patria
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Mixed Convection ◽  
Newtonian Fluid ◽  
Hartmann Number ◽  
Reverse Flow ◽  
Vertical Channel ◽  
Boussinesq Approximation ◽  
Immiscible Fluids ◽  
Induced Magnetic Field

This paper concerns the study of the influence of an external magnetic field on the reverse flow occurring in the steady mixed convection of two Newtonian immiscible fluids filling a vertical channel under the Oberbeck–Boussinesq approximation. The two isothermal boundaries are kept either at different or at equal temperatures. The velocity, the temperature, and the induced magnetic field are obtained analytically. The results are presented graphically and discussed for various values of the parameters involved in the problem (in particular, the Hartmann number and the buoyancy coefficient) and are compared with those for a single Newtonian fluid. The occurrence of the reverse flow is explained and carefully studied.

Heat and mass transfer investigation of a chemically reactive Burgers nanofluid with an induced magnetic field over an exponentially stretching surface

2021 ◽  
pp. 095440892110349
Author(s):  
Muhammad N Khan ◽  
Sohail Nadeem ◽  
Nadeem Abbas ◽  
AM Zidan
Keyword(s):  
Magnetic Field ◽  
Fluid Velocity ◽  
Comparative Investigation ◽  
Heat Transfer Analysis ◽  
Stretching Surface ◽  
Induced Magnetic Field ◽  
Coupled Equations ◽  
Exponentially Stretching Surface ◽  
Exponentially Stretching ◽  
The Impact

The flow of a chemically reactive Burgers nanofluid with an induced magnetic field over an exponentially stretching surface is considered in this analysis. The thermal slip and concentration slip boundary conditions are considered to analyze the flow at the exponentially stretching surface in the current analysis. Furthermore, a heat transfer analysis is presented with the influence of heat generation/absorption and a variable thermal conductivity effect. Appropriate similarity variables are used to transfer the flow model into the coupled ordinary differential equations. These coupled equations are computed numerically by using the Boundary value problem (BVP) midrich technique. The impact of emerging parameters is examined graphically. It is found that the fluid velocity augments for the several values of relaxation parameters, while it shows the opposite trend for the retardation parameter. Further, it is found that the transfer rate of heat and mass boosted by increasing the values of relaxation and retardation parameters. A comparative investigation of the present article with the prevailing literature shows a remarkable agreement.

scholarly journals Gravitation modulation impact on MHD free convection flow of micropolar fluid

2020 ◽  
Vol 17 (2) ◽  
pp. 199-218
Author(s):  
Sanjib Sengupta ◽  
Reshmi Deb
Keyword(s):  
Magnetic Field ◽  
Skin Friction ◽  
Micropolar Fluid ◽  
Perturbation Technique ◽  
Rotational Velocity ◽  
Fluid Velocity ◽  
Magnetic Reynolds Number ◽  
Convection Flow ◽  
Induced Magnetic Field ◽  
Modulation Parameter

In this paper, a theoretical study is carried out on unsteady three dimensional, laminar, free convective flow of micropolar fluid with Hall effect, Joule heating and heat sink under gravitation modulation. A uniform transverse magnetic field is applied normal to the plate along the fluid region. The magnetic Reynolds number is considered to be small due to incomparability of applied and induced magnetic field, as such the influence of induced magnetic field can be neglected. The multi parameter perturbation technique is used to solve the governed dimensionless equations. The fluid velocity profile, temperature profile and the concentration profiles are discussed with the aid of graphs and tables. The coefficient of skin friction and couple stresses are numerically computed in addition to Nusselt number and Sherwood number. The result reveals that the linear velocity increases due to escalation in gravitation modulation parameter values but for intensification in values of gravitation modulation parameter, a reverse effect is observed for the rotational velocity. A comparative analysis shows that the skin friction coefficient is less in micropolar fluid than the corresponding Newtonian fluids.

scholarly journals Impacts of Chemical Reaction, Diffusion-Thermo and Radiation on Unsteady Natural Convective Flow past an Inclined Vertical Plate under Aligned Magnetic Field

2021 ◽  
Vol 11 (5) ◽  
pp. 13252-13267
Keyword(s):  
Magnetic Field ◽  
Chemical Reaction ◽  
Vertical Plate ◽  
Closed Form Solution ◽  
Reaction Diffusion ◽  
Form Solution ◽  
Transform Method ◽  
The Laplace Transform ◽  
First Order Chemical Reaction ◽  
Aligned Magnetic Field

In this article, diffusion-thermo, thermal radiation, and first-order chemical reaction effects are studied analytically when the aligned magnetic field set to the fluid/ the plate on the unsteady, free convective fluid passing through an inclined vertical plate by flexible surface conditions, concentration diffusion under the action of a coaxial magnetic field. The governing PDE's are derived from the physical model and transformed into dimensionless form. Then a closed-form solution is obtained using the Laplace transform method. The effects of controlling parametric quantities like M, R, Sc, Pr, Du, Gr, Gm are analyzed through graphs for fluid properties. A comparative study has been made with published results in the absence of some non-dimensional parameters for a particular case (aligned magnetic field set to the fluid) found in good agreement.

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