MHD Couple Stress Fluid Research Articles

Thermodynamic survey of a reactive MHD couple stress fluid through saturated porous substances with convective boundary conditions

This study explores the thermodynamic behavior of a reactive hydromagnetic liquid flowing through permeable materials, with convective cooling applied to the walls. This study holds practical significance in optimization of thermal management systems and it is crucial for enhancing the efficiency of controlling thermal runaway. The flow is modeled as a system of partial differential equations which are numerically solved. The modified Adomian Decomposition Method and Pade approximation technique are utilized in solving the equations. The results acquired for velocity and temperature distributions are thereby employed to estimate entropy generation rate with critical values over numerous effects of various boundaries over improvement of thermal runaway utilizing Pade approximation technique to show the significant impact of convective cooling term (Biot number) and other thermophysical parameters on the fluid flow. The outcomes show that fluid velocity continuously increases with rising values of inverse couple stress and fluid temperature increases Biot number.

MHD Couple stress fluid between two concentric spheres with slip regime

The problem of the axisymmetric steady flow of an incompressible couple stress fluid within two concentric spheres is analyzed analytically in this study. In the interior of the solid sphere, translation takes place with a uniform velocity, and in the exterior, translation takes place with a fixed velocity. A study of slip conditions was carried out on the surfaces of the two spheres. In terms of stream functions, modified Bessel functions provide an analytical solution to the problem. As the outer sphere remains stationary, the inner sphere experiences the normalized drag force. A graphic representation of drag is provided based on the slip and spin slip parameters, the couple stress parameter, the separation distance, and the MHD parameter. In addition, the results are compared with earlier results for special cases of translation of one rigid sphere through an unbounded magnetic medium, viscous fluid flow, and Couple stress fluid without MHD between two concentric spheres.

Bio-Convective Hartmann Flow of Couple Stress Hybrid Nanofluid Between Two Dilating Parallel Walls with Heat and Mass Transfer

The study of bio-convective flow of hybrid nanofluid attracted many researchers because of tremendous applications in the fields of biofuel biotechnology, enzyme-based biosensors and biomedical science. The present work addresses a comparative study of CuO/Al2O3-water and CuO-water nanoparticles on heat and mass transfer characteristics of the squeezing flow of MHD couple stress fluid between two parallel plates by suspending motile micro-organisms. An approximated numerical technique (Shooting method along with Runge-Kutta 4th order scheme) have been employed to analyse the system of coupled nonlinear ordinary differential equations. The above numerical investigations were carried out for various governing parameters such as couple stress parameter, Hartmann number, bioconvection Peclet number, squeezing parameter etc. The effects of these physical parameters are illustrated graphically over velocity components, temperature distribution, diffusion of concentration and density of motile microorganisms. In addition to this the numerical values of skin friction, the local Nusselt number and local Sherwood number are tabulated at the upper plate for CuO-water and CuO–Al2O3-water at the expanding and squeezing cases. The numerical results for temperature profiles are in good consistency with earlier research.

Impact of slippage on the wall correction rotation factor of MHD couple stress fluid between two concentric spheres

The creeping rotational motion of a magnetohydrodynamic couple stress fluid between two concentric spheres under the impact of slippages. The slippage conditions are applied on the surface of the inside sphere. In addition, the couple stresses on the boundary are assumed to vanish. The analytical solution to the problem is used to obtain the field functions of velocity, tangential stress, and couple stresses. The wall correction factor experienced by the fluid on the inner solid sphere is evaluated and plotted. However, in the presence of a magnetic field, the eddy current caused by rotating particles produces a torque that tends to rise because the assumption of the torque direction is the opposite direction of magnetic induction. Also, the first couple stress parameter, the angular velocity ratio, and slip condition did an improvement in the torque. On the other side, the wall correction factor slows down with slippage on the inner sphere and the size parameter. All results give limiting cases with no slippage and viscous fluid.

Unsteady Two Dimensional Mixed Convection MHD Couple Stress Fluid Flow through an Inclined Stretching Sheet with Chemical Reaction

In this work, the investigation has focused on the unsteady hydromagnetic mixed convection couple stress fluid through an inclined linearly stretching sheet. The model equations governing the flow are converted to ordinary differential equations employing appropriate similarity transformation variables. An efficient technique, Runge-Kutta 4th order (RK4) technique together with shooting method is deployed to tackle the dimensionless equations with relevant boundary conditions. The impacts of various parameters such as unsteadiness parameter , Hartman number , mixed convection parameter , concentration buoyancy parameter , angle of inclination , chemical reaction parameter and Schmidt number are analysed and discussed with plots. Fluid velocity decreases as the unsteadiness, Hartman number, Schmidt number, and chemical reaction parameters rise; while the angle of inclination, mixed convection, and concentration buoyancy parameters speed up the flow. Furthermore, the unsteadiness, angle of inclination and mixed convection parameters reduce fluid temperature, while all the parameters reduce flow concentration.

Hall effects on MHD couple stress fluid flow through a vertical microchannel subjected to heat generation: A numerical study

AbstractThe present study analyzes the irreversibility in an electrically conducting couple stress fluid between two vertical channel plates with the aspects of exponential space and temperature‐dependent, radiative heat flux, heat generation, and Joule heating. A reduced system of the governing equations is obtained via applying suitable nondimensional variables. To determine the solutions of velocity, thermal field, irreversibility, and irreversibility ratio, the Runge‐Kutta‐Fehlberg method along with the shooting technique has been employed. The various pertinent parameters that are involved in the problem have been discussed in detail through graphs. The results show that the entropy production can improve with the viscous dissipation, Joule heating, exponential space and temperature‐dependent, and radiative heat flux. Furthermore, it is clear that the entropy enhances with wall ambient temperature difference, radiation parameter, and the effect is reversed with higher estimations of the fluid wall interaction parameter, couple stress parameter, and rarefaction. The present numerical results are compared with the existing results that are in good agreement.

Porous curved annular plates lubricated with MHD-Couple stress fluid

Porous curved annular plates lubricated with MHD-Couple stress fluid

Heat and mass transfer analysis of MHD couple stress fluid flow through expanding or contracting porous pipe with cross diffusion effects

This article investigates the effects of an incompressible laminar magnetohydrodynamic flow of couple stress fluid through an expanding or contracting porous pipe with cross diffusion has been considered. It is assumed that the pipe wall expands or contracts uniformly at time dependent rate. The system of governing partial differential equations and with associate boundary conditions are transformed into non-linear coupled system of equations by using suitable similarity transformations and obtained a solution by homotopy analysis method based Mathematica package BVPh2.0. The behaviour of various non-dimensional important parameters on velocity profiles, temperature and concentration distributions and also the rate of heat and mass transfers are studied and exhibited in the form of graphs. We noticed that the temperature of the fluid is enhanced by cross diffusion effects, whereas the concentration of the fluid decreased. In addition, the concentration of the fluid is decreased as Hartmann and inverse Darcy’s parameters increase.

Porous exponential slider bearings lubricated with MHD-couple stress fluid

PurposeThe purpose of this study is to examine the magneto-hydrodynamic (MHD) effect on porous exponential slider bearings lubricated with couple stress fluid and to derive the modified Reynolds’s equation for non-Newtonian fluid under various operating conditions to obtain the optimum bearing parameters.Design/methodology/approachBased upon the MHD theory and Stokes theory for couple stress fluid, the governing equations relevant to the problem under consideration are derived. This paper analyzes the effect on porous exponential slider bearings with an electrically conducting fluid in the presence of a transverse magnetic field. Semi-numerical solutions are obtained and discussed.FindingsIt is found that there is an increase in the load carrying capacity, frictional force and decrease in the co-efficient of friction in porous bearings due to the presence of magnetic effects with couple stress fluid.Originality/valueThis study is relatively original and gives the MHD effect on porous exponential slider bearings lubricated with couple stress fluid. The author believes that the paper presents these results for the first time.

Chemical reaction in peristaltic motion of MHD couple stress fluid in channel with Soret and Dufour effects

Abstract This paper looks at the peristaltic motion of MHD couple stress fluid in an inclined asymmetric channel. Simultaneous effects of heat and mass transfer are considered. Soret and Dufour features lead to the coupled differential systems. Channel walls satisfy the convective conditions of heat and mass transfer. Exact solutions for the stream function and pressure gradient are derived. Temperature and concentration are obtained numerically. Graphical illustrations for axial velocity, temperature, concentration and streamline patterns are developed. Physical interpretation of obtained results has been presented. It can be seen that both Soret and Dufour numbers reduce the concentration field while reverse effect is seen towards temperature for both numbers. It is also observed that concentration reduces towards destructive chemical reaction and enhances for constructive chemical reaction. The heat transfer Biot number gives rise to fluid temperature. Further more the mass transfer Biot number decreases the concentration.

Colloidal study of unsteady magnetohydrodynamic couple stress fluid flow over an isothermal vertical flat plate with entropy heat generation

The present work aims to examine the entropy heat generation analysis for unsteady MHD couple stress fluid flow over a uniformly heated vertical flat plate. The mathematical model of this problem is given by highly time reliant non-linear coupled equations and resolved by an efficient unconditionally stable implicit scheme. The time histories of average values of momentum and heat transport coefficients, entropy and Bejan lines, as well as the steady-state flow variables, discussed for several values of non-dimensional parameters arising in the flow equations. Results specify that time required to attain the time independent flow with respect to the flow field variables get amplified with the augmented values of couple stress parameter. The outcomes also indicate that entropy generation parameter upsurges with rising values of group parameter and Grashof number while the reverse trend is observed for couple stress parameter and magnetic parameter.

Transport of MHD Couple Stress Fluid Through Peristalsis in a Porous Medium Under the Influence of Heat Transfer and Slip Effects

An attempt has been made to examine the effects of magnetohydrodynamic couple stress fluid in peristaltic flow with porous medium under the impact of slip, heat transfer and wall properties. The expressions are obtained for temperature, coefficient of heat transfer and velocity. Influences of different parameters, the Hartmann number, Brinkman number and adaptability parameters on the temperature and warmth trade coefficient are discussed through outlines.

An MHD couple stress fluid due to a perforated sheet undergoing linear stretching with heat transfer

We investigate an MHD couple stress liquid due to a perforated sheet undergoing linear stretching with radiation. The liquid is initially at rest with its activity is restricted by pulling the two sheet ends with parallel and identical forces. The consequential movement of the or else quiescent fluid is consequently generated exclusively by the stirring plate that develops a linearly varied speed with the distance from the slit. In addition to fluid flow, heat transfer with two cases of different boundary conditions from the sheet is considered, the first with prescribed surface temperature and, the second with prescribed heat flux. The arising set of non-linear coupled nonlinear partial differential equations is rehabilitated into non-linear ordinary differential equations and then exact expressions are derived for velocity and by means of a power series method with Kummer’s confluent hyper-geometric functions for temperature.

EFFECTS OF CHEMICAL REACTION AND THERMAL RADIATION ON HEAT GENERATED STRETCHING SHEET IN A COUPLE STRESS FLUID FLOW

theoretical steady of two-dimensional and MHD couple stress fluid flow over a linearly stretching sheet is investigated with the effects of thermal radiation, internal heat generation and homogeneous chemical reaction of first order. The governing equations of continuity, momentum, energy and diffusion for this boundary layer flow are transformed into one set of coupled non-linear ordinary differential equations using the local similarity transformation and are then solved using the fourth-order Runge-Kutta method along with the shooting technique. The effects of the couple stress parameter ( S ), Magnetic parameter ( M ) and chemical reaction parameter ( Cr ) are presented through the graphical illustrations. It has been found from the results that the temperature of the couple stress fluid is enhanced due to increases in Pr,Ec,M and Q but decreased with R and S . Increase in the couple stress parameter ( S ) enhances the flow velocity but enhance in the magnetic field ( M ) reduces the flow velocity.

Effects of Heat and Mass Transfer on the Peristaltic Transport of MHD Couple Stress Fluid through Porous Medium in a Vertical Asymmetric Channel

The intrauterine fluid flow due to myometrial contractions is peristaltic type motion and the myometrial contractions may occur in both symmetric and asymmetric directions. The channel asymmetry is produced by choosing the peristaltic wave train on the walls to have different amplitude, and phase due to the variation of channel width, wave amplitudes and phase differences. In this paper, we study the effects of heat and mass transfer on the peristaltic transport of magnetohydrodynamic couple stress fluid through homogeneous porous medium in a vertical asymmetric channel. The flow is investigated in the wave frame of reference moving with constant velocity with the wave. The governing equations of couple stress fluid have been simplified under the long wave length approximation. The exact solutions of the resultant governing equations have been derived for the stream function, temperature, concentration, pressure gradient, and heat transfer coefficients. The pressure difference and frictional forces at both the walls are calculated using numerical integration. The influence of diverse flow parameters on the fluid velocity, pressure gradient, temperature, concentration, pressure difference, frictional forces, heat transfer coefficients, and trapping has been discussed. The graphical results are also discussed for four different wave shapes. It is noticed that increasing of couple stresses and heat generation parameter increases the size of the trapped bolus. The heat generation parameter increases the peristaltic pumping and temperature.