Ion-slip Currents Research Articles

Numerical study of dispersion of nanoparticles in magnetohydrodynamic liquid with Hall and ion slip currents

Heat transfer in partially ionized Erying-Powell liquid containing four types of nano-particles is discussed in this manuscript. Mathematical models for the mixture Erying-Powell plasma and nano-particles are developed and are solved by using finite element method (FEM). Numerical computations are carried out under tolerance 10-5. Physical parameters have significant effects on both thermal boundary layer thicknesses and momentum boundary layer thicknesses. Shear stresses at the surface can be minimized by the Hall and ion slip currents whereas the shear stresses at the sheet for Erying-Powell fluid are high as comparing to the Newtonian fluid. The rate of transfer of heat is significantly influenced by Hall and ion slip parameters. Highest rate of transfer of heat is observed for the case of TiO2 nano-particles. Therefore, it is recommended to disperse TiO2 nano-particles in Erying-Powell fluid for enhancement of heat transfer in Erying-Powell plasma.

Radiation, dissipation and Dufour effects on MHD free convection Casson fluid flow through a vertical oscillatory porous plate with ion-slip current

Radiation, dissipation and Dufour effects on MHD free convection Casson fluid flow through a vertical oscillatory porous plate with ion-slip current

Unsteady MHD natural convection flow of a rotating viscoelastic fluid over an infinite vertical porous plate due to oscillating free-stream

PurposeThe purpose of this paper is to present an analytical study on an unsteady magnetohydrodynamic (MHD) boundary layer flow of a rotating viscoelastic fluid over an infinite vertical porous plate embedded in a uniform porous medium with oscillating free-stream taking Hall and ion-slip currents into account. The unsteady MHD flow in the rotating fluid system is generated due to the buoyancy forces arising from temperature and concentration differences in the field of gravity and oscillatory movement of the free-stream.Design/methodology/approachThe resulting partial differential equations governing the fluid motion are solved analytically using the regular perturbation method by assuming a very small viscoelastic parameter. In order to note the influences of various system parameters and to discuss the important flow features, the numerical results for fluid velocity, temperature and species concentration are computed and depicted graphically vs boundary layer parameter whereas skin friction, Nusselt number and Sherwood number at the plate are computed and presented in tabular form.FindingsAn interesting observation is recorded that there occurs a reversal flow in the secondary flow direction due to the movement of the free stream. It is also noted that a decrease in the suction parameter gives a rise in momentum, thermal and concentration boundary layer thicknesses.Originality/valueVery little research work is reported in the literature on non-Newtonian fluid dynamics where unsteady flow in the system arises due to time-dependent movement of the plate. The motive of the present analytical study is to analyse the influences of Hall and ion-slip currents on unsteady MHD natural convection flow of a rotating viscoelastic fluid (non-Newtonian fluid) over an infinite vertical porous plate embedded in a uniform porous medium with oscillating free-stream.

Unsteady MHD Natural Convective Flow of a Rotating Fluid over an Infinite Vertical Plate due to Oscillatory Movement of the Free-Stream with Hall and Ion-Slip Currents

In the present research study a mathematical analysis has been presented for unsteady MHD natural convective flow of a rotating fluid over an infinite vertical plate immersed in a fluid saturated porous medium with oscillating free-stream. The effects of Hall and ion-slip currents also considered on the fluid flow. The unsteady MHD flow over the vertical plate is induced due to thermal and concentration buoyancy forces and oscillatory movement of the free-stream. The partial differential equations governing the motion for the fluid flow are solved analytically. The effects of various pertinent flow parameters on the fluid velocity, fluid temperature and species concentration are presented in graphical form whereas that on skin friction and rate of heat and mass transfer at the plate are presented in tabular form. An interesting observation recorded from the present analysis that there appears reversal flow in the secondary flow direction due to presence of thermal and/or concentration buoyancy forces. However, in the absence of both reversals flow does not exist in the secondary flow direction. It is also noted that the thickness of momentum boundary layer decreases with rise in frequency of oscillations of the free-stream.

Influence of Hall and ion-slip currents on unsteady MHD free convective flow of a rotating fluid past an oscillating vertical plate

Influence of Hall and ion-slip currents on unsteady MHD free convective flow of a rotating fluid past an oscillating vertical plate

Finite element study of three dimensional radiative nano-plasma flow subject to Hall and ion slip currents

Abstract In this article, we developed a computer code of Galerikan Finite Element method (GFEM) for three dimensional flow equations of nano-plasma fluid (blood) in the presence of uniform applied magnetic field when Hall and ion slip current are significant. Lorentz force is calculated through generalized Ohm’s law with Maxwell equations. A series of numerical simulations are carried out to search η max and algebraic equations are solved by Gauss-Seidel method with simulation tolerance 10 - 8 . Simulated results for special case have an excellent agreement with the already published results. Velocity components and temperature of the nano-plasma (blood) are influenced significantly by the inclusion of nano-particles of Copper (Cu) and Silver (Ag). Heat enhancement is observed when copper and silver nonmagnetic nanoparticles are used instead of simple base fluid (conventional fluid). Radiative nature of nano-plasma in the presence of magnetic field causes a decrease in the temperature due to the transfer of heat by the electromagnetic waves. In contrast to this, due to heat dissipated by Joule heating and viscous dissipation phenomena, temperature of nano-plasmaincreases as thermal radiation parameter is increased. Thermal boundary layer thickness can be controlled by using radiative fluid instead of non-radiative fluid. Momentum boundary layer thickness can be reduced by increasing the intensity of the applied magnetic field. Temperature of plasma in the presence magnetic field is higher than the plasma in the absence of magnetic field.

Heat transfer analysis in peristaltic slip flow with Hall and ion-slip currents

This work is devoted to the study of heat transfer effects in peristaltically induced flow of an electrically conducting viscous fluid in an asymmetric channel. An incompressible fluid fills the porous space in a channel. Analysis is made in the presence of Hall and ion-slip effects. The effects of velocity and thermal slips at the boundaries are considered. The problems which govern the fluid flow and heat transfer are modeled in the wave frame of reference. Exact solutions have been constructed under realistic assumptions. Important features of peristaltic motion and heat transfer are studied with the varying values of Hall parameter, ion-slip parameter, Hartman number, permeability parameter, velocity slip parameter and thermal slip parameter. The graphical results for the field quantities are given in detail.

Unsteady MHD Free Convection and Mass Transfer Flow Through a Vertical Oscillatory Porous Plate in a Rotating Porous Medium with Hall, Ion-slip Currents and Heat Source

The analytical solution is made on the unsteady flow of an electrically conducting viscous incompressible fluid bounded by an infinite vertical porous plate. The plate executes harmonic oscillation at a frequency n in its own plane. The governing equations of the problem contain coupled partial differential equations. The dimensionless equations are solved analytically using perturbation technique. The effect of various parameters of the problem on the velocity, temperature and concentration field within the boundary layer are discussed and shown graphically.
 Dhaka Univ. J. Sci. 64(2): 91-98, 2016 (July)

Influence of Cross-Diffusion on Slip Flow and Heat Transfer of Chemically Reacting UCM Fluid between Porous Parallel Plates with Hall and Ion Slip Currents

The present paper deals with the Hall and ion slip currents on an incompressible unsteady free convection flow and heat transfer of an upper convected Maxwell fluid between porous parallel plates with Soret and Dufour effects by considering the velocity slip and convective boundary conditions. Assume that there are periodic injection and suction at the lower and upper plates, respectively. The temperature and concentration at the lower and upper plates change periodically with time. The flow field equations are reduced to nonlinear ordinary differential equations by using similarity transformations and a semi-analytical-numerical solution has been obtained by the differential transform method. The velocity components, temperature distribution, and concentration with respect to different fluid and geometric parameters are discussed in detail and presented in the form of graphs. It is observed that the Biot number increases the temperature and concentration of the fluid. Further, the concentration of the fluid is enhanced whereas the temperature decreases with increasing slip. The present results are compared with the existing literature and are found to be in good agreement.

HEAT AND MASS TRANSFER ANALYSIS IN VARIABLE VISCOSITY PERISTALTIC FLOW WITH HALL CURRENT AND ION-SLIP

In this paper, we investigate the effects of heat and mass transfer on peristaltic motion of magnetohydrodynamic (MHD) viscous fluid in a symmetric channel in the presence of Hall and ion-slip currents, viscous and Joule dissipations, and variable temperature-dependent viscosity. The governing field equations are solved using series solution under the normal assumptions of long wavelength and low Reynolds number. The pumping characteristics are obtained using numerical integration. The results are critically analyzed for the physical parameters that characterize the peristaltic motion. These parameters include amplitude ratio, volume flow rate, viscosity parameter, Brinkman number, heat generation parameter, magnetic parameter, Hall parameter and ion-slip parameter. The results are presented graphically to understand the behavior of the field quantities and the physics of peristaltic transport of physiological and industrial fluids. Special emphasis has been given to analyze the effects of heat transfer with viscous and Joule dissipations — essentially the new features added in this study.

Chemically reacting micropolar fluid flow and heat transfer between expanding or contracting walls with ion slip, Soret and Dufour effects

The aim of the present study is to investigate the Hall and ion slip currents on an incompressible free convective flow, heat and mass transfer of a micropolar fluid in a porous medium between expanding or contracting walls with chemical reaction, Soret and Dufour effects. Assume that the walls are moving with a time dependent rate of the distance and the fluid is injecting or sucking with an absolute velocity. The walls are maintained at constant but different temperatures and concentrations. The governing partial differential equations are reduced into nonlinear ordinary differential equations by similarity transformations and then the resultant equations are solved numerically by quasilinearization technique. The results are analyzed for velocity components, microrotation, temperature and concentration with respect to different fluid and geometric parameters and presented in the form of graphs. It is noticed that with the increase in chemical reaction, Hall and ion slip parameters the temperature of the fluid is enhanced whereas the concentration is decreased. Also for the Newtonian fluid, the numerical values of axial velocity are compared with the existing literature and are found to be in good agreement.

MHD free convection flow of Eyring–Powell fluid from vertical surface in porous media with Hall/ionslip currents and ohmic dissipation

A mathematical study is presented to analyze the nonlinear, non-isothermal, magnetohydrodynamic (MHD) free convection boundary layer flow, heat and mass transfer of non-Newtonian Eyring–Powell fluid from a vertical surface in a non-Darcy, isotropic, homogenous porous medium, in the presence of Hall currents and ionslip currents. The governing nonlinear coupled partial differential equations for momentum conservation in the x, and z directions, heat and mass conservation, in the flow regime are transformed from an (x,y,z) coordinate system to a (ξ,η) coordinate system in terms of dimensionless x-direction velocity (f′) and z-direction velocity (G), dimensionless temperature and concentration functions (θ and ϕ) under appropriate boundary conditions. Both Darcian and Forchheimer porous impedances are incorporated in both momentum equations. Computations are also provided for the variation of the x and z direction shear stress components and also heat and mass transfer rates. It is observed that with increasing ɛ, primary velocity, secondary velocity, heat and mass transfer rates are decreased whereas, the temperature, concentration and skin friction are increased. An increasing δ is found to increase primary and secondary velocities, skin friction, heat and mass transfer rates. But the temperature and concentration decrease. Increasing βe and βi are seen to increase primary velocity, skin friction, heat and mass transfer rates whereas secondary velocity, temperature and concentration are decreased. Excellent correlation is achieved with a Nakamura tridiagonal finite difference scheme (NTM). The model finds applications in magnetic materials processing, MHD power generators and purification of crude oils.

Computational Study of MHD Free Convection Flow of Non-Newtonian Tangent Hyperbolic Fluid from a Vertical Surface in Porous Media with Hall/Ionslip Currents and Ohmic Dissipation

A numerical study is presented to analyze the nonlinear, non-isothermal, magnetohydrodynamic (MHD) free convection boundary layer flows of non-Newtonian tangent hyperbolic fluid past a vertical surface in a non-Darcy, isotropic, homogenous porous medium in the presence of Hall currents and Ionslip currents. The governing nonlinear coupled partial differential equations for momentum conservation in x and z directions, heat and mass conservation in the flow regime are transformed from an (x, y, z) coordinate system to (\(\upxi ,\upeta \)) coordinate system in terms of dimensionless x-direction velocity (\(f^{\prime }\)) and z-direction velocity (G), dimensionless temperature and concentration functions (\(\uptheta \) and \(\upphi \)) under appropriate boundary conditions. Both Darcian and Forchheimer porous impedances are incorporated in both momentum equations. Computations are also provided for the variation of the x and z direction shear stress components and also heat and mass transfer rates. Increasing Weissenberg number (We) is observed to decrease primary and secondary velocity and concentration but increase temperature. It is found that the primary and secondary velocity is increased with increasing power law index (n) whereas the temperature and concentration are decreased. Increasing hall and Ionslip current (\(\beta _{e}\) and \(\beta _{i}\)) is observed to increase primary velocity but decreases secondary velocity, temperature and concentration. Increasing magnetic parameter (\(N_{m}\)) is seen to decrease primary velocity but decreases secondary velocity, temperature and concentration. Increasing Darcy number (Da) is found to increase primary and secondary velocity whereas decreases temperature and concentration. Increasing Forchheimer parameter (Fs) is seen to decrease primary and secondary velocity but increases temperature and concentration. The model finds applications in magnetic materials processing, MHD power generators and purification of crude oils.

Slip-flow and heat transfer of chemically reacting micropolar fluid through expanding or contracting walls with Hall and ion slip currents

Abstract The present article deals with the effects of velocity slip, chemical reaction on heat and mass transfer of micropolar fluid in expanding or contracting walls with Hall and ion slip currents. Assume that there is symmetric suction or injection along the channel walls, which are maintained at nonuniform constant temperatures and concentrations. The governing Navier–Stokes equations are reduced to nonlinear ordinary differential equations by using similarity transformations then solved numerically by quasilinearization technique. The effects of various parameters such as wall expansion ratio, chemical reaction parameter, Prandtl number, Schmidt number, slip parameter, Hall and ion slip parameters on nondimensional velocity components, microrotation, temperature and concentration are discussed in detail through graphs. It is observed that the concentration of the fluid is enhanced with viscosity. Further, the temperature and concentration of the fluid are increased whereas the microrotation is decreased for an expansion or contraction of the walls.

Computational solutions for non-isothermal, nonlinear magneto-convection in porous media with hall/ionslip currents and ohmic dissipation

A theoretical and numerical study is presented to analyze the nonlinear, non-isothermal, magnetohydrodynamic (MHD) free convection boundary layer flow and heat transfer in a non-Darcian, isotropic, homogenous porous medium, in the presence of Hall currents, Ionslip currents, viscous heating and Joule heating. A power-law variation is used for the temperature at the wall. The governing nonlinear coupled partial differential equations for momentum conservation in the x and z directions and heat conservation, in the flow regime are transformed from an (x, y, z) coordinate system to a (ξ,η) coordinate system in terms of dimensionless x-direction velocity (∂F/∂η) and z-direction velocity (G) and dimensionless temperature function (H) under appropriate boundary conditions. Both Darcian and Forchheimer porous impedances are incorporated in both momentum equations. Computations are also provided for the variation of the x and z direction shear stress components and also local Nusselt number. Excellent correlation is achieved with a Nakamura tridiagonal finite difference scheme (NTM). The model finds applications in magnetic materials processing, MHD power generators and purification of crude oils.

MHD Free Convection and Mass Transfer Flow through a Vertical Oscillatory Porous Plate with Hall, Ion-slip Currents and Heat Source in a Rotating System

Unsteady MHD free convection and mass transfer flow through a vertical oscillatory porous plate with hall, ion-slip currents and heat source in a rotating system are studied. The governing equations of the problem contain a system of non-linear coupled partial differential equations. The coupled non-linear partial differential equations are solved by explicit finite difference method and the numerical results have been calculated by Compaq Visual 6.6a. For good accuracy, stability and convergence analysis have been analyzed. The results of this investigation are discussed for the different values of the well-known parameters and are shown graphically.

Unsteady Heat and Mass Transfer of Chemically Reacting Micropolar Fluid in a Porous Channel with Hall and Ion Slip Currents.

This paper presents an incompressible two-dimensional heat and mass transfer of an electrically conducting micropolar fluid flow in a porous medium between two parallel plates with chemical reaction, Hall and ion slip effects. Let there be periodic injection or suction at the lower and upper plates and the nonuniform temperature and concentration at the plates are varying periodically with time. The flow field equations are reduced to nonlinear ordinary differential equations using similarity transformations and then solved numerically by quasilinearization technique. The profiles of velocity components, microrotation, temperature distribution and concentration are studied for different values of fluid and geometric parameters such as Hartmann number, Hall and ion slip parameters, inverse Darcy parameter, Prandtl number, Schmidt number, and chemical reaction rate and shown in the form of graphs.

Hall and ion slip effects on peristaltic flow and heat transfer analysis with Ohmic heating

The peristaltic transport of a magnetohydrodynamic (MHD) fluid is examined for both symmetric and asymmetric channels. Hall and ion slip effects are taken into account. The heat transfer is analyzed by considering the effects of viscous and Ohmic dissipations. The relevant flow problems are first modeled, and then the closed form solutions are constructed under the assumptions of long wavelength and low Reynolds number. The solutions are analyzed through graphical illustration. It is noted that the velocity increases but the temperature decreases with the increases in the Hall and ion slip parameters. The axial pressure gradient is less in magnitude in the presence of Hall and ion slip currents. The Hall and ion slip effects are to decrease the maximum pressure against which peristalsis works as a pump. The free pumping flux decreases with the increases in the Hall and ion slip parameters. The increases in the Hall and ion slip parameters result in an increase in the size of the trapped bolus.

Influence of thermal radiation and heat generation/absorption on MHD heat transfer flow of a micropolar fluid past a wedge considering hall and ion slip currents

In this paper a numerical model is developed to examine the effect of thermal radiation on magnetohydrodynamic heat transfer flow of a micropolar fluid past a non-conducting wedge in presence of heat source/sink. In the model it is assumed that the fluid is viscous, incompressible and electrically conducting. The Hall and ion slip effects have also been taken into consideration. The model contains highly non-linear coupled partial differential equations which have been converted into ordinary differential equation by using the similarity transformations. These equations are then solved numerically by Shooting technique along with the Runge-Kutta-Fehlberg integration scheme for entire range of parameters with appropriate boundary conditions. The effects of various parameters involved in the problem have been studied with the help of graphs. Numerical values of skin friction coefficients and Nusselt number are presented in tabular form. The results showed that the micropolar fluids are better to reduce local skin drag as compared to Newtonian fluids and the presence of heat sink increases the heat transfer rate.

Time-dependent MHD Couette flow of rotating fluid with Hall and ion-slip currents

The unsteady magnehydrodynamics (MHD) Couette flow of an electrically conducting fluid in a rotating system is investigated by taking the Hall and ion-slip currents into consideration. The derived fundamental equations on the assumption of a small magnetic Reynolds number are solved analytically with the well-known Laplace transform technique. The unified closed-form expressions are obtained for the velocity and the skin friction in the two different cases of the magnetic field being fixed to either the fluid or the moving plate. The effects of various parameters on the velocity and the skin friction are discussed by graphs. The results reveal that the primary and secondary velocities increase with the Hall current. An increase in the ion-slip parameter also leads to an increase in the primary velocity but a decrease in the secondary velocity. It is also shown that the combined effect of the rotation, Hall, and ion-slip parameters determines the contribution of the secondary motion in the fluid flow.