scholarly journals Mixed Convection Magnetohydrodynamics Flow of a Nanofluid with Heat Transfer: A Numerical Study

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Abdul Quayam Khan ◽  
Amer Rasheed
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Mixed Convection ◽  
Thermal Radiation ◽  
Numerical Study ◽  
Time Derivative ◽  
Moving Plate ◽  
Finite Difference Discretization ◽  
The Mathematical Model ◽  
Fluid Parameters

In this paper we have studied the magnetohydrodynamic (MHD) mixed convection Maxwell flow of an incompressible nanofluid with magnetic field and heat transfer over a moving plate aligned horizontally. Thermal radiation has also been applied in order to investigate its effects on velocity and temperature variations in the fluid. The Caputo time derivative has been employed to derive the mathematical model. A numerical solution has been obtained using finite difference discretization along with L1-algorithm. Fractional and other pertinent physical fluid parameters like magnetic field parameter, thermal radiation, effect on velocity, and temperature distribution are analyzed and demonstrated through graphs.

Integrated Fluxes in Magneto-Hydrodynamic Mixed Convection in a Cavity Sustained by Conjugate Heat Transfer

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Orkodip Mookherjee ◽  
Shantanu Pramanik
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Heat Flux ◽  
Kinetic Energy ◽  
Mixed Convection ◽  
Conjugate Heat Transfer ◽  
Numerical Study ◽  
Horizontal Magnetic Field ◽  
Flow And Heat Transfer ◽  
Stationary Interface

Abstract A numerical study of magneto-hydrodynamic mixed convection in a cavity has been conducted to investigate the influence of magnetic field on integrated flux of thermal energy, linear momentum, and kinetic energy. Shear force through lid motion establishes the forced convection effect and buoyancy force due to differential heating of the moving lid and the stationary interface ensures the natural convection phenomenon. Additionally, conduction through the solid slab with prescribed temperature at the outer surface attached to the cavity induces conjugate heat transfer. Further, the top and bottom walls throughout the domain are kept insulated and a uniform horizontal magnetic field is applied on the interface toward left. Fluid flow and heat transfer characteristics are examined for a range of Hartmann number (Ha): 0, 10, 50, and 120 at fixed values of Reynolds number, Grashof number, and Prandtl number of 300, 9 × 104 and 0.71, respectively. The result shows that the transport of heat in the near wall regions of the fluid domain is primarily governed by diffusion, whereas advection appears stronger in the central region of the cavity. Increase in magnetic field strength from Ha = 0 to 120 gradually suppresses the recirculating structure of the flow signifying a reduction in advective strength as depicted by the decrease in the value of total integrated heat flux from 25.15×10-3 to 6.0×10-3. The reduction in heat flux, momentum fluxes, and kinetic energy fluxes with increase in magnetic field has been well correlated in the range of 0≤Ha≤120.

Numerical study of unsteady MHD Couette flow and heat transfer of nanofluids in a rotating system with convective cooling

2016 ◽  
Vol 26 (5) ◽  
pp. 1567-1579 ◽  
Author(s):  
Ahmada Omar Ali ◽  
Oluwole Daniel Makinde ◽  
Yaw Nkansah-Gyekye
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Couette Flow ◽  
Numerical Study ◽  
Integration Scheme ◽  
Parallel Plates ◽  
Content Type ◽  
Flow And Heat Transfer ◽  
Mhd Couette Flow ◽  
Rotating Channel

Purpose – The purpose of this paper is to investigate numerically the unsteady MHD Couette flow and heat transfer of viscous, incompressible and electrically conducting nanofluids between two parallel plates in a rotating channel. Design/methodology/approach – The nanofluid is set in motion by the combined action of moving upper plate, Coriolis force and the constant pressure gradient. The channel rotates in unison about an axis normal to the plates. The nonlinear governing equations for velocity and heat transfer are obtained and solved numerically using semi-discretization, shooting and collocation (bvp4c) techniques together with Runge-Kutta Fehlberg integration scheme. Findings – Results show that both magnetic field and rotation rate demonstrate significant effect on velocity and heat transfer profiles in the system with Cu-water nanofluid demonstrating the highest velocity and heat transfer efficiency. These numerical results are in excellent agreements with the results obtained by other methods. Practical implications – This paper provides a very useful source of information for researchers on the subject of hydromagnetic nanofluid flow in rotating systems. Originality/value – Couette flow of nanofluid in the presence of applied magnetic field in a rotating channel is investigated.

scholarly journals Improved Energy Efficiency of Mixed Convection Heating Process in Eccentric Annulus

2021 ◽  
Vol 13 (8) ◽  
pp. 168781402110391
Author(s):  
Ben Abdelmlek Khaoula ◽  
Ben Nejma Fayçal
Keyword(s):  
Heat Transfer ◽  
Energy Efficiency ◽  
Rayleigh Number ◽  
Mixed Convection ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Rotation Speed ◽  
Numerical Study ◽  
Heating Process ◽  
Eccentric Annulus

This paper deals with a numerical study of mixed convection heat transfer in horizontal eccentric annulus. The inner cylinder is supposed hot and rotating, however the outer one is kept cold and motionless. The numerical problem was solved using COMSOL Multiphysics® which is based on finite element method. The resolution of the partial differential equations was conducted through an implicit scheme with the use of the damped Newton’s method. The present numerical analysis concerns the effect of eccentricity, rotation speed and Rayleigh number on the flow patterns, heat transfer rate, and energy efficiency of the process. It was found that the heat transfer rate increases with the increase of Rayleigh number. In addition, the heat transfer rate drops with the increase of rotation speed. Finally, we have demonstrated that maximum energy efficiency is achieved not only with higher Rayleigh number but also it is maximum with small eccentricity.

scholarly journals Periodic mixed convection flow along the surface of a thermally and electrically conducting cone

2020 ◽  
Vol 24 (Suppl. 1) ◽  
pp. 225-235
Author(s):  
Asifa Ilyas ◽  
Muhammad Ashraf
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Mixed Convection ◽  
Current Density ◽  
Magnetic Force ◽  
Convection Flow ◽  
Force Parameter ◽  
Mixed Convection Flow ◽  
Hydromagnetic Waves ◽  
Periodic Components

The main aim of the present work is to highlight the significances of periodic mixed convection flow and heat transfer characteristics along the surface of magnetized cone by exerting magnetic field exact at the surface of the cone. The numerical simulations of coupled non-dimensional equations are computed in terms of velocity field, temperature and magnetic field concentration and then used to examine the periodic components of skin friction, ?w, heat transfer, qw, and current density, jw, for various governing parameters. A nice periodic behavior of heat transfer qw is concluded for each value of mixed convection parameter, ?, but maximum periodicity is sketched at ? = 50. It is also computed that the lower value of magnetic Prandtl number ? = 0.1 gets poor amplitude in current density but highest amplitude is sketched for higher ? = 0.5. The behavior of heat and fluid-flow in the pres?ence of aligned magnetic field is associated with the phase angle and amplitude of oscillation. It is also noted that due to the increase in magnetic force parameter, ?, there are wave like disturbances generate within the fluid layers. These disturbances are basically hydromagnetic waves which becomes more prominent as the strength of magnetic force parameter is increased.

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