scholarly journals MHD CASSON NANOFLUID FLOW OVER A STRETCHING SURFACE EMBEDDED IN A POROUS MEDIUM: EFFECTS OF THERMAL RADIATION AND SLIP CONDITIONS

2021 ◽  
Vol 51 (4) ◽  
pp. 229-239
Author(s):  
Sameh E. Ahmed ◽  
R.A Mohamed ◽  
A.M Ali ◽  
A.J Chamkha ◽  
M.S Soliman
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Thermal Radiation ◽  
Numerical Study ◽  
Physical Parameters ◽  
Radiation Parameter ◽  
Two Phase ◽  
Casson Nanofluid ◽  
Non Linear ◽  
The Magnetic Field

This article presents a numerical study for a magnetohydrodynamic flow of a non-Newtonian Casson nanofluid over a stretching sheet embedded in a porous medium under the impacts of non-linear thermal radiation, heat generation/absorption, Joule heating and slips boundary conditions. A two-phase nanofluid model is applied to represent the nanofluid mixture. The porous medium is represented via the Darcy model. A similar solution is obtained for the governing equations and a numerical treatment based on the Runge-Kutta method is conducted to the resulting system of equations.  In this study, the controlling physical parameters are the Casson fluid parameter , the magnetic field , the radiation parameter , the Brownian motion parameter  and the thermophoresis parameter . The obtained results reveal that an increase in the Casson parameter enhances both of the local Nusselt and the Sherwood number while they are reduced as the non-linear radiation parameter increases. In addition, an increase in the magnetic field parameter supports the skin friction coefficient regardless the value of the Casson parameter.

scholarly journals MHD and Thermal Radiation Effects on Exponentially Accelerated Isothermal Vertical Plate with Uniform Mass Diffusion

2013 ◽  
Vol 18 (2) ◽  
pp. 599-608
Author(s):  
R. Muthucumaraswamy ◽  
V. Visalakshi
Keyword(s):  
Magnetic Field ◽  
Thermal Radiation ◽  
Radiation Effects ◽  
Vertical Plate ◽  
Mass Diffusion ◽  
Field Parameter ◽  
Physical Parameters ◽  
Radiation Parameter ◽  
Grashof Number ◽  
Magnetic Field Parameter

Thermal radiation effects on an unsteady free convective flow of a viscous incompressible flow of a past an exponentially accelerated infinite isothermal vertical plate with uniform mass diffusion in the presence magnetic field are considered. The fluid considered here is a gray, absorbing-emitting radiation but a non-scattering medium. The plate temperature is raised to Tw and the concentration level near the plate is also raised to Cʹw . An exact solution to the dimensionless governing equations is obtained by the Laplace transform method, when the plate is exponentially accelerated with a velocity u= u0 exp(aʹtʹ) in its own plane against gravitational field. The effects of velocity, temperature and concentration fields are studied for different physical parameters such as the magnetic field parameter, thermal radiation parameter, Schmidt number, thermal Grashof number, mass Grashof number and time. It is observed that the velocity increases with decreasing magnetic field parameter or radiation parameter. But the trend is just reversed with respect to a or t .

SPECTRAL NUMERICAL STUDY OF ENTROPY GENERATION IN MAGNETO-CONVECTIVE VISCOELASTIC BIOFLUID FLOW THROUGH PORO-ELASTIC MEDIA WITH THERMAL RADIATION AND BUOYANCY EFFECTS

2021 ◽  
pp. 1-36
Author(s):  
Bandaru Mallikarjuna ◽  
Srinivas Jangili ◽  
G. Gopi Krishna ◽  
O. A. Beg ◽  
Ali Kadir
Keyword(s):  
Magnetic Field ◽  
Thermal Radiation ◽  
Entropy Generation ◽  
Numerical Study ◽  
Physical Models ◽  
Viscous Drag ◽  
Radiation Parameter ◽  
Viscoelastic Parameter ◽  
Thermal Buoyancy ◽  
Flow Through

Abstract Electromagnetic high-temperature therapy is popular in medical engineering treatments for various diseases include tissue damage ablation repair, hyperthermia and oncological illness diagnosis. The simulation of transport phenomena in such applications requires multi-physical models featuring magnetohydrodynamics, biorheology, heat transfer and deformable porous media. Motivated by investigating the fluid dynamics and thermodynamic optimization of such processes, in the present article a mathematical model is developed to study the combined influence of thermal buoyancy, magnetic field and thermal radiation on the fluid and heat characteristics in electrically-conducting viscoelastic biofluid flow through a vertical deformable porous medium. Jefferys elastic-viscous model is deployed to simulate non-Newtonian characteristics of the biofluid. It is assumed that heat is generated within the fluid by both viscous and Darcy (porous matrix) dissipations. The boundary value problem is normalized with appropriate transformations. The non-dimensional biofluid velocity, solid displacement and temperature equations with appropriate boundary conditions are solved computationally using a spectral method. Verification of accuracy is conducted via monitoring residuals of the solutions and Validated with shooting technique is included. The effects of Jeffrey viscoelastic parameter, viscous drag parameter, magnetic field parameter, radiation parameter and buoyancy parameter on flow velocity, solid displacement, temperature and entropy generation are depicted graphically and interpreted at length. Increasing magnetic field and drag parameters are found to reduce the field velocity, solid displacement, temperature and entropy production. Higher magnitudes of thermal radiation parameter retard the flow and decrease Nusselt number whereas they elevate solid displacement.

Numerical exploration of the combined effects of non-linear thermal radiation and variable thermo-physical properties on the flow of Casson nanofluid over a wedge

2017 ◽  
Vol 13 (4) ◽  
pp. 628-647 ◽  
Author(s):  
Archana M. ◽  
Gireesha B.J. ◽  
Prasannakumara B.C. ◽  
Rama Subba Reddy Gorla
Keyword(s):  
Differential Equations ◽  
Thermal Radiation ◽  
Physical Properties ◽  
Physical Parameters ◽  
Content Type ◽  
Casson Nanofluid ◽  
Linear Ordinary Differential Equations ◽  
Similarity Transformations ◽  
Non Linear ◽  
Thermo Physical Properties

Purpose The effect of non-linear thermal radiation and variable thermo-physical properties are investigated in the Falkner-Skan flow of a Casson nanofluid in the presence of magnetic field. The paper aims to discuss this issue. Design/methodology/approach Selected bunch of similarity transformations are used to reduce the governing partial differential equations into a set of non-linear ordinary differential equations. The resultant equations are numerically solved using Runge-Kutta-Fehlberg fourth-fifth-order method along with shooting technique. Findings The velocity, temperature and concentration profiles are evaluated for several emerging physical parameters and are analyzed through graphs and tables in detail. Research limitations/implications This study only begins to reveal the research potential and pitfalls of research and publishing on boundary-layer flow, heat and mass transfer of Casson nanofluid past and the moving and static wedge-shaped bodies. Originality/value It is found that the presence of non-linear thermal radiation and variable properties has more influence in heat transfer. Furthermore, temperature profile increases as the radiation parameter increases.

Two-Dimensional Simulation of Magnetohydrodynamic Two-Phase Flow in Random Porous Media Using the Lattice Boltzmann Method

2010 ◽  
Author(s):  
Mahshid Hadavand ◽  
Aydin Nabovati ◽  
Antonio C. M. Sousa
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Phase Flow ◽  
Two Dimensional ◽  
Two Phase ◽  
Single Relaxation Time ◽  
Boltzmann Method ◽  
The Magnetic Field

The present work employs the single relaxation time lattice Boltzmann method along with the pseudo potential model for the two-phase flow simulation of a ferrofluid in a random two-dimensional medium under the influence of a spatially variable external magnetic field. The magnetic field is created and controlled by placing a permanent magnet at the outlet end of the channel filled with a porous medium. The magnitude of the magnetic force acting on the ferrofluid is controlled by changing the distance of the magnet from the channel outlet. The spatially variable magnetic field strength was analytically calculated inside the channel using the available relations in the literature. The main goal of the present work is to qualitatively study the applicability of the single relaxation time (SRT) lattice Boltzmann method (LBM) to modelling flow of a ferrofluid and its steering into porous media. Penetration of the ferrofluid into the porous medium, which is initially filled with a fluid with no magnetic properties, was simulated in time. The simulation results for the flow front are presented and the effect of the magnetic field strength on the rate of flow penetration and front advancement was studied qualitatively. The LBM has proved to be a powerful tool for modelling flows, which involve multi-physics in complex geometries, when mesoscopic inter-particle forces and interaction with external complex forces have to be determined.

scholarly journals Numerical Study of the Effect of Magnetic Field on Nanofluid Heat Transfer in Metal Foam Environment

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Hamid Shafiee ◽  
Elaheh NikzadehAbbasi ◽  
Majid Soltani
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Porous Medium ◽  
Porous Media ◽  
Fluid Flow ◽  
Volume Fraction ◽  
Numerical Study ◽  
Computational Simulation ◽  
Thermodynamic Efficiency ◽  
Two Phase

The magnetic field can act as a suitable control parameter for heat transfer and fluid flow. It can also be used to maximize thermodynamic efficiency in a variety of fields. Nanofluids and porous media are common methods to increase heat transfer. In addition to improving heat transfer, porous media can increase pressure drop. This research is a computational simulation of the impacts of a magnetic field induced into a cylinder in a porous medium for a volume fraction of 0.2 water/Al2O3 nanofluid with a diameter of 10 μm inside the cylinder. For a wide variety of controlling parameters, simulations have been made. The fluid flow in the porous medium is explained using the Darcy-Brinkman-Forchheimer equation, and the nanofluid flow is represented utilizing a two-phase mixed approach as a two-phase flow. In addition, simulations were run in a slow flow state using the finite volume method. The mean Nusselt number and performance evaluation criteria (PEC) were studied for different Darcy and Hartmann numbers. The results show that the amount of heat transfer coefficient increases with increasing the number of Hartmann and Darcy. In addition, the composition of the nanofluid in the base fluid enhanced the PEC in all instances. Furthermore, the PEC has gained its highest value at the conditions relating to the permeable porous medium.

scholarly journals The Magneto-Natural Convection Flow of a Micropolar Hybrid Nanofluid Over a Vertical Plate Saturated in a Porous Medium

Fluids ◽  
2021 ◽  
Vol 6 (6) ◽  
pp. 202
Author(s):  
A. Mahdy ◽  
E. R. El-Zahar ◽  
A. M. Rashad ◽  
W. Saad ◽  
H. S. Al-Juaydi
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Nusselt Number ◽  
Friction Coefficient ◽  
Skin Friction ◽  
Skin Friction Coefficient ◽  
Hybrid Nanofluid ◽  
Non Linear ◽  
The Magnetic Field ◽  
Linear Odes

In this study, we investigate the convective flow of a micropolar hybrid nanofluid through a vertical radiating permeable plate in a saturated porous medium. The impact of the presence or absence of the internal heat generation (IHG) in the medium is examined as well as the impacts of the magnetic field and thermal radiation. We apply similarity transformations to the non-dimensionalized equations and render them as a system of non-linear ODEs (Ordinary Differential Equations) subject to appropriate boundary conditions. This system of non-linear ODEs is solved by an adaptive mesh transformation Chebyshev differential quadrature method. The influence of the governing parameters on the temperature, microrotation and velocity is examined. The skin friction coefficient and the Nusselt number are tabulated. We determine that the skin friction coefficient and heat transport rate increase with the increment in the magnetic field. Moreover, the increment in the micropolarity and nanoparticle volume fraction enhances the skin friction coefficient and the Nusselt number. We also conclude that the IHG term improved the flow of the hybrid nanofluid. Finally, our results indicate that employing a hybrid nanofluid increases the heat transfer compared with that in pure water and a nanofluid.

HEXAGON-STRIPE TRANSITION AT THE MAGNETIC FIELD INDUCED PHASE TRANSFORMATIONS OF THE MAGNETORHEOLOGICAL SUSPENSIONS

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2345-2351 ◽  
Author(s):  
A. CEBERS
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Physical Parameters ◽  
Phase Boundaries ◽  
Modulated Phases ◽  
Magnetorheological Suspensions ◽  
Perturbed State ◽  
Magnetorheological Suspension ◽  
The Magnetic Field ◽  
Hele Shaw Cell

The phase diagram of the magnetorheological suspension allowing for the modulated phases in the Hele-Shaw cell under the action of the normal field is calculated. The phase boundaries between the stripe, the hexagonal and the unmodulated phases in dependence on the layer thickness and the magnetic field strength are found. The existence of the transitions between the stripe and the hexagonal phases at the corresponding variation of the physical parameters is illustrated by the numerical simulation of the concentration dynamics in the Hele-Shaw cell. It is remarked that those transitions in the case of the magnetorheological suspensions can be caused by the compression or the expansion of the layer. Among the features noticed at the numerical simulation of the concentration dynamics in the Hele-Shaw cell are: the stripe patterns formed from the preexisting hexagonal structures are more ordered than arising from the initial randomly perturbed state; at the slightly perturbed boundary between the concentrated and diluted phases the hexagonal and the inverted hexagonal phases are formed and others.

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