Effect of Magnetic Field on Fluid Flow and Heat Transfer of a Nanofluid in a Vertical Channel with Heat Sources

This paper focuses on solving the fluid flow and heat transfer equations inside a two-dimensional square enclosure containing three hot obstacles affected by gravity and magnetic force placed on a ramp using Boltzmann method (LBM) applying multiple relaxation times (MRT). Although, the Lattice Boltzmann with MRT is a complex technique, it is a relatively new, stable, fast and high-accurate one. The main objective of this research was to numerically model the fluid flow and ultimately obtaining the velocity field, flow and temperature contour lines inside a two-dimensional enclosure. The results and their comparisons for different types of heat transfer revealed that free or forced heat transfer has a considerable impact on the heat transfer and stream lines. This can be controlled by modifying the Richardson number. It is revealed that changing the intensity of the magnetic field (Hartman number) has an appreciable effect on the heat transfer.

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Unsteady Magnetohydrodynamic Mixed Convective Flow of a Reactive Casson Fluid in a Vertical Channel Filled with a Porous Medium

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.408.33 ◽

2021 ◽

Vol 408 ◽

pp. 33-49

Author(s):

Lazarus Rundora

Keyword(s):

Magnetic Field ◽

Heat Transfer ◽

Porous Medium ◽

Fluid Flow ◽

Vertical Channel ◽

Casson Fluid ◽

Convection Flow ◽

Temperature Dependent ◽

Temperature Dependent Viscosity ◽

Dependent Viscosity

This article analyses the thermal decomposition in an unsteady MHD mixed convection flow of a reactive, electrically conducting Casson fluid within a vertical channel filled with a saturated porous medium and the influence of the temperature dependent properties on the flow. The fluid is assumed to be incompressible with the viscosity coefficient varying exponentially with temperature. The flow is subjected to an externally applied uniform magnetic field. The exothermic chemical kinetics inherent in the flow system give rise to heat dissipation. A technique based on a semi-discretization finite difference scheme and the shooting method is applied to solve the dimensionless governing equations. The effects of the temperature dependent viscosity, the magnetic field and other important parameters on the velocity and temperature profiles, the wall shear stress and the wall heat transfer rate are presented graphically and discussed quantitatively and qualitatively. The fluid flow model revealed flow characteristics that have profound ramifications including the increased heat transfer enhancement attributes of the reactive temperature dependent viscosity Casson fluid flow.

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Analytical Investigation of Nusselt Number and Skin Friction of Fluid Flow Over a Stretching Sheet Using Optimal Homotopy Asymptotic Method

Advanced Science Engineering and Medicine ◽

10.1166/asem.2020.2570 ◽

2020 ◽

Vol 12 (5) ◽

pp. 657-661

Author(s):

Zohreh Aliannejadi

Keyword(s):

Magnetic Field ◽

Heat Transfer ◽

Boundary Layer ◽

Nusselt Number ◽

Fluid Flow ◽

Differential Equations ◽

Skin Friction ◽

Flow And Heat Transfer ◽

Optimal Homotopy Asymptotic Method ◽

The Magnetic Field

In many cases such as production of metal sheets, the behavior of fluid flow and heat transfer in the neighborhood of a hot plate is very important. The CFD simulation of fluid flow is a widespread study that reveals detail information about the fluid flow in the calculated domain. In this study, the flow and heat transfer of a specific fluid in the above area of a stretching plate is examined analytically to find the variation of skin friction and Nusselt number. For this purpose, the similarity transformations can be employed to achieve the ordinary differential equations from the governing partial differential equations. The optimal homotopy asymptotic method (OHAM) is used to solve the ordinary differential equations which is applicable in solving of nonlinear equations. The effects of magnetic field on the analytical results from solving the equations are evaluated in detail. It is found that the thickness of the flow boundary layer decreases and the thickness of the thermal boundary layer increases by increasing in the magnetic field. Moreover, the Nusselt number is lower and skin friction is higher for the higher values of the magnetic field.

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Investigation of fluid flow and heat transfer in a vertical channel heated from one side by PV elements, part II - Experimental study

Renewable Energy ◽

10.1016/0960-1481(96)88857-4 ◽

1996 ◽

Vol 8 (1-4) ◽

pp. 254-258 ◽

Cited By ~ 46

Author(s):

M. Sandberg ◽

B. Moshfegh

Keyword(s):

Heat Transfer ◽

Experimental Study ◽

Fluid Flow ◽

Vertical Channel ◽

Flow And Heat Transfer

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Combined Effects of Magnetic Field and Thermal Radiation on Fluid Flow and Heat Transfer of Mixed Convection in a Vertical Cylindrical Annulus

Journal of Heat Transfer ◽

10.1115/1.4032609 ◽

2016 ◽

Vol 138 (6) ◽

Cited By ~ 5

Author(s):

Ben-Wen Li ◽

Wei Wang ◽

Jing-Kui Zhang

Keyword(s):

Magnetic Field ◽

Heat Transfer ◽

Fluid Flow ◽

Mixed Convection ◽

Axial Magnetic Field ◽

Outer Cylinder ◽

Mhd Equations ◽

Temperature Fields ◽

Flow And Heat Transfer ◽

Cylindrical Annulus

Magnetohydrodynamic (MHD, also for magnetohydrodynamics) mixed convection of electrically conducting and radiative participating fluid is studied in a differentially heated vertical annulus. The outer cylinder is stationary, and the inner cylinder is rotating at a constant angular speed around its axis. The temperature difference between the two cylindrical walls creates buoyancy force, due to the density variation. A constant axial magnetic field is also imposed to resist the fluid motion. The nonlinear integro-differential equation, which characterizes the radiation transfer, is solved by the discrete ordinates method (DOM). The MHD equations, which describe the magnetic and transport phenomena, are solved by the collocation spectral method (CSM). Detailed numerical results of heat transfer rate, velocity, and temperature fields are presented for 0≤Ha≤100, 0.1≤τL≤10, 0≤ω≤1, and 0.2≤εW≤1. The computational results reveal that the fluid flow and heat transfer are effectively suppressed by the magnetic field as expected. Substantial changes occur in flow patterns as well as in isotherms, when the optical thickness and emissivity of the walls vary in the specified ranges. However, the flow structure and the temperature distribution change slightly when the scattering albedo increases from 0 to 0.5, but a substantial change is observed when it increases to 1.

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