MHD free convection flow in a vertical porous super-hydrophobic micro-channel

2020 ◽  
pp. 095440892096505
Author(s):  
BK Jha ◽  
BJ Gwandu
Keyword(s):  
Slip Surface ◽  
Hydrophobic Surface ◽  
Transverse Magnetic ◽  
Convection Flow ◽  
Fluid Temperature ◽  
Micro Channel ◽  
Channel One ◽  
Electrically Conducting ◽  
Micro Fluidics ◽  
Temperature Jump Coefficient

A free convective flow of an incompressible and electrically conducting fluid through a vertical micro-channel of rectangular geometry was considered. Both plates were porous and heated alternately. A transverse magnetic field was applied across the channel. One channel wall surface was no slip and the other was super-hydrophobic. The purpose of the study is to examine the effects of super-hydrophobicity, magnetism and wall porosity on the main characteristics of the flow. The exact solutions of the formulated differential equations were provided. A few highlights of the results obtained include: (1) the magnetic parameter lowered the skin friction at both surfaces when either of them were heated, (2) the suction/injection parameter raised the fluid temperature when the super-hydrophobic surface (SHS) was heated and brought it down when the no slip surface (NSS) was heated, (3) a critical temperature jump coefficient was observed at which the flow rates in both cases (only SHS heated, and only NSS heated) were equal. A few application areas of the research include micro-fluidics and micro-electronics.

scholarly journals Combined effect of conduction and viscous dissipation on magnetohydrodynamic free convection flow along a vertical flat plate

1970 ◽  
Vol 4 (2) ◽  
pp. 87-98 ◽  
Author(s):  
Abdullah Al-Mamun ◽  
Nur Hosain Md Ariful Azim ◽  
Md. Abdul Maleque
Keyword(s):  
Viscous Dissipation ◽  
Numerical Solutions ◽  
Transverse Magnetic ◽  
Convection Flow ◽  
Electrically Conducting ◽  
Temperature Distributions ◽  
Two Dimensional Flow ◽  
Marine Engineering ◽  
Energy Equations ◽  
Conjugate Conduction

This paper concerns the effects of conduction and viscous dissipation on natural convection flow of an incompressible, viscous and electrically conducting fluid in the presence of transverse magnetic field. Numerical solutions for the governing momentum and energy equations are given. A discussion has been provided for the effects of magnetic parameter, Prandtl number, conjugate conduction parameter and viscous dissipation parameter on two-dimensional flow. Results for the details of the velocity, temperature distributions as well as the skin friction and the rate of heat transfer are shown graphically. Also the numerical values of the surface temperature distributions are presented in tabular form.DOI: http://dx.doi.org/10.3329/jname.v4i2.992 Journal of Naval Architecture and Marine Engineering Vol.4(2) 2007 p.87-98

scholarly journals Skin-friction for unsteady free convection MHD flow between two heated vertical parallel plates

2006 ◽  
Vol 33 (4) ◽  
pp. 259-280 ◽  
Author(s):  
Gopal Singha ◽  
P.N. Deka
Keyword(s):  
Free Convection ◽  
Skin Friction ◽  
Mhd Flow ◽  
Reynolds Numbers ◽  
Magnetic Reynolds Number ◽  
Convection Flow ◽  
Fluid Temperature ◽  
Parallel Plates ◽  
Electrically Conducting ◽  
Induced Field

Unsteady viscous incompressible free convection flow of an electrically conducting fluid between two heated vertical parallel plates is considered in the presence of a uniform magnetic field applied transversely to the flow. The induce field along the lines of motion varies transversely to the flow and the fluid temperature changing with time. An analytical solution for velocity, induced field and the temperature distributions are obtained for small and large magnetic Reynolds numbers. The skin-friction at the two plates is obtained. Velocity distribution, induced field and skin-friction are plotted against the distance from the plates. It has been observed that with the increase in Rm, the magnetic Reynolds number, at constant M, the Hartmann number, leads to an increase in the skin-friction gradually. But with the increase in M, at constant Rm, the skin-friction decreases.

scholarly journals Thermal Radiation Effect on Fully Developed Natural Convection Flow in a Vertical Micro-Channel

2021 ◽  
Vol 28 (2) ◽  
pp. 20-28
Author(s):  
B. Aina
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Thermal Radiation ◽  
Temperature Jump ◽  
Velocity Slip ◽  
Convection Flow ◽  
Physical Situation ◽  
Fluid Temperature ◽  
Micro Channel ◽  
Natural Convection Flow

The effect of thermal radiation on steady fully developed natural convection flow in a vertical micro-channel is presented in this article. Effects of velocity slip and temperature jump conditions are taken into account due to their counter effects on both the volume flow rate and the rate of heat transfer. Due to the presence of thermal radiation, the momentum and energy equations are coupled system of ordinary differential equations. Governing coupled nonlinear equations are solved analytically by employing the perturbation analysis method to obtain an expression for fluid temperature, fluid velocity, rate of heat transfer and skin friction on the microchannel walls. The effect of various parameters controlling the physical situation such as thermal radiation, temperature difference, Knudsen number, and fluid wall interaction are discussed with the aid of line graphs and Tables. Results indicate that both velocity and temperature enhanced with the increase of the thermal radiation parameter. Keywords: Thermal radiation, Natural convection, Micro-channel, Velocity slip, Temperature jump

scholarly journals Radiation effects on unsteady MHD free convection with Hall current near an infinite vertical porous plate

2001 ◽  
Vol 26 (4) ◽  
pp. 249-255 ◽  
Author(s):  
Mohamed A. Seddeek ◽  
Emad M. Aboeldahab
Keyword(s):  
Magnetic Field ◽  
Free Convection ◽  
Radiation Effects ◽  
Porous Plate ◽  
Transverse Magnetic ◽  
Convection Flow ◽  
Suction Velocity ◽  
Electrically Conducting ◽  
Vertical Porous Plate ◽  
Effects Of Radiation

Radiation effect on unsteady free convection flow of an electrically conducting, gray gas near equilibrium in the optically thin limit along an infinite vertical porous plate are investigated in the presence of strong transverse magnetic field imposed perpendicularly to the plate, taking Hall currents into account. A similarly parameter length scale (h), as a function of time and the suction velocity are considered to be inversely proportional to this parameter. Similarity equations are then derived and solved numerically using the shooting method. The numerical values of skin friction and the rate of heat transfer are represented in a table. The effects of radiation parameter, Hall parameter, and magnetic field parameters are discussed and shown graphically.

scholarly journals Thermo-diffusion effects on the magnetohydrodynamic natural convection flow of a chemically reactive Brinkman type nanofluid in a porous medium

2019 ◽  
Vol 51 (2) ◽  
pp. 168-179 ◽  
Author(s):  
G. S. Seth ◽  
R. Kumar ◽  
R. Tripathi
Keyword(s):  
Natural Convection ◽  
Skin Friction ◽  
Fluid Velocity ◽  
Surface Concentration ◽  
Convection Flow ◽  
Fluid Temperature ◽  
Species Concentration ◽  
Electrically Conducting ◽  
Laplace Transform Technique ◽  
Mass Transfers

An investigation on the unsteady MHD natural convection heat and mass transfer flow of an electrically conducting, viscous, incompressible, chemically reactive and heat-absorbing nanofluid of Brinkman type past an exponentially accelerated moving vertical plate with ramped wall temperature and ramped surface concentration is carried out. Governing equations are non-dimensionalized and Laplace Transform Technique is used to find the exact solutions for fluid velocity, fluid temperature and species concentration. The quantities of physical interest, i.e. skin friction, rates of heat and mass transfers at the plate are also calculated. Numerical results for the velocity, temperature and species concentration of the fluid are demonstrated with the help of graphs whereas those of skin friction, rate of heat and mass transfers at the plate are displayed in tables for various flow parameters.

scholarly journals Effect of Heat Generation (Absorption) on Unsteady MHD flow over a Truncated Cone Embedded in a Stable Thermally Stratified Environment

2021 ◽  
Vol 8 (S1-Feb) ◽  
pp. 87-96
Author(s):  
Ashwini G
Keyword(s):  
Skin Friction ◽  
Heat Generation ◽  
Nonlinear Partial Differential Equations ◽  
Mhd Flow ◽  
Transverse Magnetic ◽  
Stratified Medium ◽  
Convection Flow ◽  
Transfer Coefficients ◽  
Electrically Conducting ◽  
Truncated Cone

This paper examines the effect of heat generation (absorption) on unsteady free convection flow of an incompressible electrically conducting fluid over a truncated cone embedded in a thermally stratified medium in the presence of a transverse magnetic field. The governing nonlinear partial differential equations have been solved numerically, using an efficient implicit finite difference scheme along with quasilinearization technique. The numerical results for skin-friction coefficients and velocity components in x- and y- directions, Nusselt number and temperature profiles are obtained and analyzed for different values of governing parameters. It is observed that, heat generation increases skin friction and decreases heat transfer coefficients, whereas opposite trend is observed during heat absorption. Also it is found that heat generation has a significant effect on temperature profile.

Magnetohydrodynamic unsteady free convective flow through a porous medium bounded by an infinite vertical porous plate

1986 ◽  
Vol 64 (1) ◽  
pp. 84-89 ◽  
Author(s):  
Nabile T. El Dabe
Keyword(s):  
Porous Medium ◽  
Porous Plate ◽  
Transverse Magnetic ◽  
Convection Flow ◽  
Electrically Conducting ◽  
Vertical Porous Plate ◽  
Flow Phenomena ◽  
Permeability Parameter ◽  
Flow Through ◽  
K Permeability

Unsteady, free convection flow of an incompressible electrically conducting viscous liquid through a porous medium past a hot, vertical, porous plate in the presence of a transverse magnetic field has been studied in this paper. The flow phenomena have been characterized by the nondimensional numbers P (Prandtl number), G (Grashoff number), M (magnetic number), W (frequency parameter), and K (permeability parameter). The effect of these parameters on the velocity and temperature distribution, the skin friction, and the heat flux have been tabulated and represented graphically.

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