Double Diffusive Marangoni Convection Flow of Electrically Conducting Fluid in a Square Cavity With Chemical Reaction

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
M. Saleem ◽  
M. A. Hossain ◽  
Suvash C. Saha
Keyword(s):  
Magnetic Field ◽  
Nusselt Number ◽  
Sherwood Number ◽  
Average Nusselt Number ◽  
Marangoni Convection ◽  
Convection Flow ◽  
Square Cavity ◽  
Electrically Conducting ◽  
Electrically Conducting Fluid ◽  
Double Diffusive

Double diffusive Marangoni convection flow of viscous incompressible electrically conducting fluid in a square cavity is studied in this paper by taking into consideration of the effect of applied magnetic field in arbitrary direction and the chemical reaction. The governing equations are solved numerically by using alternate direct implicit (ADI) method together with the successive over relaxation (SOR) technique. The flow pattern with the effect of governing parameters, namely the buoyancy ratio W, diffusocapillary ratio w, and the Hartmann number Ha, is investigated. It is revealed from the numerical simulations that the average Nusselt number decreases; whereas the average Sherwood number increases as the orientation of magnetic field is shifted from horizontal to vertical. Moreover, the effect of buoyancy due to species concentration on the flow is stronger than the one due to thermal buoyancy. The increase in diffusocapillary parameter, w causes the average Nusselt number to decrease, and average Sherwood number to increase.

Effect of Magnetic Field on Free Convection in Inclined Cylindrical Annulus Containing Molten Potassium

2015 ◽  
Vol 07 (04) ◽  
pp. 1550052 ◽  
Author(s):  
Masoud Afrand ◽  
Nima Sina ◽  
Hamid Teimouri ◽  
Ali Mazaheri ◽  
Mohammad Reza Safaei ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Nusselt Number ◽  
Average Nusselt Number ◽  
Hartmann Number ◽  
Conducting Fluid ◽  
Electrically Conducting ◽  
Cylindrical Annulus ◽  
Electrically Conducting Fluid ◽  
Wide Range ◽  
The Magnetic Field

Three-dimensional (3D) numerical simulation of natural convection of an electrically conducting fluid under the influence of a magnetic field in an inclined cylindrical annulus has been performed. The inner and outer cylinders are maintained at uniform temperatures and other walls are thermally insulated. The governing equations of this fluid system are solved by a finite volume (FV) code based on SIMPLER solution scheme. Detailed numerical results of heat transfer rate, Lorentz force, temperature and electric fields have been presented for a wide range of Hartmann number (0 ≤ Ha ≤ 60) and inclination angle (0 ≤ γ ≤ 90). The results indicate that a magnetic field can control the magnetic convection of an electrically conducting fluid. Depending on the direction and strength of the magnetic field, the suppression of convective motion was observed. For vertical cylindrical annulus, increasing the strength of the magnetic field causes the loss symmetry, and as the consequence, isotherms lose their circular shape. With increasing the Hartmann number the average Nusselt number approaches a constant value. For vertical annulus, the effect of Hartmann number on the average Nusselt number is not prominent compared to the case of horizontal annulus.

Impacts of variable magnetic field on a ferrofluid flow inside a cavity including a helix using ISPH method

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abdelraheem M. Aly ◽  
Sameh Elsayed Ahmed ◽  
Zehba Raizah
Keyword(s):  
Magnetic Field ◽  
Nusselt Number ◽  
Average Nusselt Number ◽  
Volume Fraction ◽  
Heat Pumps ◽  
Variable Magnetic Field ◽  
Convection Flow ◽  
Content Type ◽  
Air Conditioners ◽  
Magnetic Source

Purpose The purpose of this paper is to study the unsteady ferrofluid flow with a hot source helix inside a cavity under the impacts of a variable magnetic field by using the incompressible smoothed particle hydrodynamics method. Design/methodology/approach The governing equations are formulated by considering the basics of the magnetohydrodynamic and ferrohydrodynamics. Different locations of a variable magnetic source outside the geometry are investigated. The helical coils are extensively applied in the cooling and heating of air conditioners and heat pumps. Computations were carried out for different lengths of the heated helix (0.2 ≤ Lh ≤ 0.8), different locations of the magnetic source, (a = 0.5, b = −0.01), (a = 0.5, b = 1.01), (a = 1.01, b = 0.5), (a = −0.01, b = 0.5), different numbers of the inner helix (one helix, two helixes and three helixes) and different values of the nanoparticles volume fraction (0% ≤ ϕ ≤ 10%). Findings The outcomes of the investigations revealed that an increase in the lengths of a helix by 0.4 results in a reduction of the stream function by 25.60%. In addition, when the magnetic wire is located near the center of the right wall, the maximum values of the average Nusselt number are obtained while the smallest values of the average Nusselt number are given when the magnetic source is located near center of the top wall. Originality/value The novelty of this paper is investigating the natural convection flow from two different models of an inner hot helix inside a cavity with considering different locations of variable magnetic sources.

Computational study on MHD power-law fluid in tilted enclosure having sinusoidal heated sidewall

2020 ◽  
Vol 16 (5) ◽  
pp. 1041-1059
Author(s):  
Minakshi Poonia
Keyword(s):  
Magnetic Field ◽  
Nusselt Number ◽  
Power Law ◽  
Inclination Angle ◽  
Average Nusselt Number ◽  
Computational Study ◽  
Convection Flow ◽  
Power Law Fluid ◽  
Left Wall ◽  
Content Type

PurposeIn the present computational study, the heat transfer and two-dimensional natural convection flow of non-Newtonian power-law fluid in a tilted rectangular enclosure is examined. The left wall of enclosure is subjected to spatially varying sinusoidal temperature distribution and right wall is cooled isothermally while the upper and lower walls are retained to be adiabatic. The flow is considered to be laminar, steady and incompressible under the influence of magnetic field. The governing mass, momentum and energy equations are transformed into dimensionless form in terms of stream function, vorticity and temperature.Design/methodology/approachThen resulted highly non-linear partial differential equations are solved computationally using Galerkin finite element method.FindingsThe exhaustive flow pattern and temperature fields are displayed through streamlines and isotherm contours for various parameters, namely, Prandtl number, Rayleigh number, Hartmann number by considering different power-law index and inclination angle. The effect of inclination angle on average Nusselt number is also shown graphically. This problem observes the potential vortex flow with elliptical core. The results show that the circular strength of the vortex formed reduces as the magnetic field strength grows. As the inclination angle increases the intensity of flow field decreases while the value of average Nusselt number increases.Originality/valueThis study has important applications in thermal management such as cooling techniques used in buildings, nuclear reactors, heat exchangers and power generators.

scholarly journals MHD Natural Convection Flow of Fluid From a Vertical Flat Plate Considering Temperature Dependent Viscosity

2010 ◽  
Vol 2 (3) ◽  
pp. 453
Author(s):  
S. F. Ahmmed ◽  
M. S. A. Sarker
Keyword(s):  
Magnetic Field ◽  
Natural Convection ◽  
Flat Plate ◽  
Variable Viscosity ◽  
Conducting Fluid ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Local Skin ◽  
Electrically Conducting ◽  
Electrically Conducting Fluid

A two-dimensional natural convection flow of a viscous incompressible and electrically conducting fluid past a vertical impermeable flat plate is considered in presence of a uniform transverse magnetic field. Here the viscosity is taken as dependent on temperature whereas the thermal conductivity is assumed constant. We also investigate the effect of magnetic field on the natural convection flow of a viscous incompressible and electrically conducting fluid. The effect of variable viscosity and magnetic field on local skin friction, the rate of heat transfer and the profiles for velocity as well as viscosity in the entire free convection regime are presented and discussed. Keywords: Natural convection; Magnethydrodynamics (MHD); Viscosity; Prandtl number.  © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i3.4776                 J. Sci. Res. 2 (3), 453-463 (2010) 

Unsteady MHD natural convection flow of a nanofluid inside an inclined square cavity containing a heated circular obstacle

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
M. A. Mansour ◽  
Rama Subba Reddy Gorla ◽  
Sadia Siddiqa ◽  
A. M. Rashad ◽  
T. Salah
Keyword(s):  
Nusselt Number ◽  
Natural Convection ◽  
Average Nusselt Number ◽  
Convection Flow ◽  
Square Cavity ◽  
Natural Convection Flow ◽  
Symmetric Pattern ◽  
Inclined Cavity ◽  
The Right ◽  
Good Agreement

Abstract The phenomena of unsteady magnetohydrodynamics (MHD) natural convection flow in an inclined square cavity filled with nanofluid and containing a heated circular obstacle at its center with heat generation/absorption impact are examined numerically. The cavity’s right and left walls are maintained at low temperatures, while the remaining walls are adiabatic. The volumetric external force, MHD, is applied across the inclined cavity. A penalty formulation-based finite element method is used to solve the nonlinear set of governing equations iteratively. The numerical scheme and results are validated through a comparison with the benchmark results, and it shows that our solutions are in good agreement with them. The results are shown in terms of contours of streamlines, isotherms, and average Nusselt number. It is observed that MHD alters the streamlines, isotherms, and average Nusselt number and dominates the flow as compared to any other physical parameter. The average Nusselt number is found sensitive to the central obstacle’s size, and it reduces sufficiently when the radius of the inner cylinder increases. For all the parameters, the streamlines’ symmetric pattern holds, such that the anti-clockwise cells on the left side of the cavity have their symmetric clockwise cells on the right side.

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