scholarly journals MHD Mixed Convection Micropolar Fluid Flow through a Rectangular Duct

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Mekonnen Shiferaw Ayano ◽  
Stephen T. Sikwila ◽  
Stanford Shateyi
Keyword(s):  
Magnetic Field ◽  
Differential Equations ◽  
Mixed Convection ◽  
Applied Magnetic Field ◽  
Flow Reversal ◽  
Convection Flow ◽  
Temperature Profiles ◽  
Rectangular Duct ◽  
Micropolar Fluid Flow ◽  
Flow Through

Mixed convection flow through a rectangular duct with at least one of the sides of the walls of the rectangle being isothermal under the influence of transversely applied magnetic field has been analyzed numerically in this study. The governing differential equations of the problem have been transformed into a system of nondimensional differential equations and then solved numerically. The dimensionless velocity, microrotation components, and temperature profiles are displayed graphically showing the effects of various values of the parameters present in the problem. The results showed that the flow field is notably influenced by the considered parameters. It is found that increasing the aspect ratio increases flow reversal, commencement of the flow reversal is observed after some critical value, and the applied magnetic field increases the flow reversal in addition to flow retardation. The microrotation components flow in opposite direction; also it is found that one component of the microrotation will show no rotational effect around the center of the duct.

Effects of Magnetic Field on an Unsteady Mixed Convection Flow of Nanofluids Containing Spherical and Cylindrical Nanoparticles

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Kalidas Das ◽  
Pinaki Ranjan Duari ◽  
Prabir Kumar Kundu
Keyword(s):  
Magnetic Field ◽  
Mass Transfer ◽  
Mixed Convection ◽  
Time Dependent ◽  
Convection Flow ◽  
Temperature Profiles ◽  
Mixed Convection Flow ◽  
Shooting Technique ◽  
Similarity Transformations ◽  
Unsteady Mixed Convection

The present article gives a ray of light on the effects of magnetic field on an unsteady mixed convection flow of nanofluids containing nanoparticles which are spherical and cylindrical in nature. The unsteadiness in the flow is mainly caused by time dependent stretching velocity and temperature of the sheet at the surface. The governing transportation equations are first transformed into ordinary differential equations by using similarity transformations and then solved by employing Runga–Kutta–Frelberg method with shooting technique. The influence of various parameters on velocity and temperature profiles as well as wall shear stress and the rate of mass transfer are discussed through graphs and tables. The results for regular fluid (water) from the study are in excellent agreement with the results reported in the literature.

scholarly journals Mixed Convection Flow over a Vertical Cone with an Applied Magnetic Field

2012 ◽  
Vol 11 (3) ◽  
pp. 105-112
Author(s):  
K R Jayakumar ◽  
A h Srinivasa ◽  
A T Eswara
Keyword(s):  
Magnetic Field ◽  
Mixed Convection ◽  
Applied Magnetic Field ◽  
Convection Flow ◽  
Mixed Convection Flow ◽  
Transfer Coefficients ◽  
Vertical Cone ◽  
Heat Transfer Coefficients ◽  
Implicit Finite Difference Scheme ◽  
Implicit Finite Difference

An analysis is performed to investigate the mixed convection flow over a vertical cone with an applied magnetic field when the axis of the cone is in line with the flow. The results have been obtained for assisting and opposing flows. The partial differential equations governing the non-similar flow have been solved by an implicit finite difference scheme in combination with the quasilinearization technique. Numerical results are reported here to account the effects of magnetic field in presence of buoyancy parameter at different stream wise locations on skin friction and heat transfer coefficients.

scholarly journals Thermal and hydrodynamic characteristics of forced and mixed convection flow through vertical rectangular channels

2008 ◽  
Vol 12 (2) ◽  
pp. 103-117
Author(s):  
Abdalla Hanafi ◽  
Safaa Mahmoud ◽  
Hesham Elbakhshawangy
Keyword(s):  
Nusselt Number ◽  
Mixed Convection ◽  
Flow Direction ◽  
Rectangular Channel ◽  
Convection Flow ◽  
Temperature Profiles ◽  
Mixed Convection Flow ◽  
Downward Flow ◽  
Flow Through ◽  
Flow Directions

This paper presents experimental and numerical studies for the case of turbulent forced and mixed convection flow of water through narrow vertical rectangular channel. The channel is composed of two parallel plates which are heated at a uniform heat flux, whereas, the other two sides of the channel are thermally insulated. The plates are of 64 mm in width, 800 mm in height, and separated from each other at a narrow gap of 2.7 mm. The Nusselt number distribution along the flow direction normalized by the Nusselt number for the case of turbulent forced convection flow is obtained experimentally with a comparison with the numerical results obtained from a commercial computer code. The quantitative determination of the nor- malized Nusselt number with respect to the dimension-less number Z = (Gr/Re21/8Pr0.5) is presented with a comparison with previous experimental results. Qualitative results are presented for the normalized temperature and velocity profiles in the transverse direction with a comparison between the forced and mixed convection flow for both the cases of upward and downward flow directions. The effect of the axial locations and the parameter Gr/Re on the variation of the normalized temperature profiles in the transverse direction for both the regions of forced and mixed convection and for both of the upward and downward flow directions are obtained. The normalized velocity profiles in the transverse directions are also determined at different inlet velocity and heat fluxes for the previous cases. It is found that the normalized Nusselt number is greater than one in the mixed convection region for both the cases of upward and downward flow and correlated well with the dimension-less parameter Z for both of the forced and mixed convection regions. The temperature profiles increase with increasing the axial location along the flow direction or the parameter Gr/Re for both of the forced and mixed convection regions, but this increase is more pronounced in the case of the mixed convection flow. For the forced convection region, the velocity profile depends only on Re with no difference between the upward and downward flow directions. Whereas, for the case of mixed convection flow, the velocity profile depends on the parameter Gr/Re with a main difference between upward and downward flow. These results are of great importance for any research reactor using plate type fuel elements or for any engineering application in which mixed convection flow through rectangular channel is encountered. .

scholarly journals Homotopy Analysis Solution of Hydromagnetic Mixed Convection Flow Past an Exponentially Stretching Sheet with Hall Current

2012 ◽  
Vol 2012 ◽  
pp. 1-26 ◽  
Author(s):  
Mohamed Abd El-Aziz ◽  
Tamer Nabil
Keyword(s):  
Magnetic Field ◽  
Mixed Convection ◽  
Convection Flow ◽  
Mixed Convection Flow ◽  
Electrically Conducting ◽  
Hall Parameter ◽  
Homotopy Analysis ◽  
Continuous Sheet ◽  
Exponentially Stretching ◽  
The Magnetic Field

The effect of thermal radiation on steady hydromagnetic heat transfer by mixed convection flow of a viscous incompressible and electrically conducting fluid past an exponentially stretching continuous sheet is examined. Wall temperature and stretching velocity are assumed to vary according to specific exponential forms. An external strong uniform magnetic field is applied perpendicular to the sheet and the Hall effect is taken into consideration. The resulting governing equations are transformed into a system of nonlinear ordinary differential equations using appropriate transformations and then solved analytically by the homotopy analysis method (HAM). The solution is found to be dependent on six governing parameters including the magnetic field parameterM, Hall parameterm, the buoyancy parameterξ, the radiation parameterR, the parameter of temperature distributiona, and Prandtl number Pr. A systematic study is carried out to illustrate the effects of these major parameters on the velocity and temperature distributions in the boundary layer, the skin-friction coefficients, and the local Nusselt number.

Flow Reversal in Opposing Mixed Convection Flow in Inclined Pipes

1989 ◽  
Vol 111 (1) ◽  
pp. 114-120 ◽  
Author(s):  
A. S. Lavine ◽  
M. Y. Kim ◽  
C. N. Shores
Keyword(s):  
Mixed Convection ◽  
Tilt Angle ◽  
Maximum Flow ◽  
Flow Reversal ◽  
Transition To Turbulence ◽  
Convection Flow ◽  
Periodic Behavior ◽  
Tube Cross Section ◽  
High Reynolds ◽  
Inclined Pipe

An experimental investigation of opposing mixed convection in an inclined pipe has been conducted. Dye injection reveals the existence of flow reversal regions. There is an optimal tilt angle that yields maximum flow reversal length. Flow reversals are seen to cause early transition to turbulence. Temperature profiles are measured across the tube cross section near the entrance to the heated section, and show the effect of tube inclination. Temperature measurements exhibit periodic behavior in the flow reversal region under some conditions, generally characterized by low tilt angle and moderate to high Reynolds and Grashof numbers. Flow visualization indicates that this periodic behavior is due to the intermittent breakdown of the flow reversal region.

scholarly journals Mixed convection of micropolar fluid on a permeable stretching surface of another quiescent fluid

2020 ◽  
Vol 16 (4) ◽  
pp. 487-492
Author(s):  
Nurazleen Abdul Majid ◽  
Nurul Farahain Mohammad ◽  
Abdul Rahman Mohd Kasim ◽  
Sharidan Shafie
Keyword(s):  
Fluid Flow ◽  
Differential Equations ◽  
Mixed Convection ◽  
Micropolar Fluid ◽  
Research Subjects ◽  
Governing Equations ◽  
Stretching Surface ◽  
Shooting Technique ◽  
Micropolar Fluid Flow ◽  
Quiescent Fluid

In recent decades, micropolar fluid has been one of the major interesting research subjects due to the numerous applications such as blood, paint, body fluid, polymers, colloidal fluid and suspension fluid. However, the behavior of micropolar fluid flow over a permeable stretching surface of another quiescent fluid with a heavier density of micropolar fluid under the condition of mixed convection is still unknown. Thus, the current work aims to investigate numerically the mixed convection of micropolar fluid flow over a permeable stretching surface of another quiescent fluid. In this research, the similarity transformation is implemented to reduce the boundary layer governing equations from partial differential equations to a system of nonlinear ordinary differential equations. Then, this model is solved numerically using shooting technique with Runge-Kutta-Gill method and applied in Jupyter Notebook using Python 3 language. The behavior of micropolar fluid in terms of velocity, skin friction, microrotation and temperature are analyzed.

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.

scholarly journals Modified boundary integral method for pressure driven MHD duct flow

1989 ◽  
Vol 12 (1) ◽  
pp. 159-174
Author(s):  
B. D. Aggarwala ◽  
P. D. Ariel
Keyword(s):  
Magnetic Field ◽  
Integral Method ◽  
Boundary Integral ◽  
Boundary Integral Method ◽  
Duct Flow ◽  
Rectangular Duct ◽  
Computationally Efficient ◽  
Electrically Conducting ◽  
Flow Through ◽  
The Magnetic Field

In this paper, we investigate the flow of a viscous, Incompressible, electrically conducting fluid through a rectangular duct in the presence of a magnetic field, when one of the boundaries perpedicular to the magnetic field is partly conducting and partly Insulating, by a modified Boundary Integral Method.Three problems are considered (i) flow through an infinite channel, (ii) flow through a rectangular duct when the conducting part is symmetrically situated, and (iii) flow through a rectangular duct when the conducting part is arbltrarily positioned.Such problems have been studied before by asymptotic means for large values of M, the Hartmann number. Hoverer, the present modification of the Boundary Integral Method renders the problem computationally efficient and provides a reliable numerical solution for all values of M. For large M, our coputation time decreases significantly.

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