Impact of Partial Slip on Magneto-Ferrofluids Mixed Convection Flow in Enclosure

2020 ◽  
Vol 12 (5) ◽  
Author(s):  
Ali J. Chamkha ◽  
A. M. Rashad ◽  
A. I. Alsabery ◽  
Z. M. A. Abdelrahman ◽  
Hossam A. Nabwey
Keyword(s):  
Heat Source ◽  
Mixed Convection ◽  
Volume Fraction ◽  
Partial Slip ◽  
Convection Flow ◽  
Mixed Convection Flow ◽  
Square Enclosure ◽  
Vertical Walls ◽  
Volume Method ◽  
Ferromagnetic Particles

Abstract Magneto-ferrofluid mixed convection flow inside a lid-driven square cavity with partial slip is investigated numerically using the finite volume method. The vertical walls of the enclosure are heated partially by a constant temperature, while the horizontal moving walls are kept adiabatic. The square enclosure is filled with a mixture of kerosene–cobalt ferrofluids. The numerical computations are obtained for various parameters of the heat source length, position of the heat source, Hartmann number, Richardson number, fraction ferromagnetic particles, and constant movement parameter. It is shown that the transfer rate is clearly affected by the augmentation of the ferromagnetic particles volume fraction under the influence of a relative magnetic field and by the opposite-direction horizontal walls movement.

Mixed convection from a discrete heater in lid-driven enclosures filled with non-Newtonian nanofluids

2016 ◽  
Vol 231 (1) ◽  
pp. 3-16 ◽  
Author(s):  
AM Rashad ◽  
MA Mansour ◽  
Rama Subba Reddy Gorla
Keyword(s):  
Nusselt Number ◽  
Heat Source ◽  
Local Nusselt Number ◽  
Volume Fraction ◽  
Fluid Model ◽  
Convection Flow ◽  
Viscosity Parameter ◽  
Volumetric Rate ◽  
Vertical Walls ◽  
Volume Method

The transport mechanism of laminar combined convection flow of an incompressible viscous non-Newtonian nanofluid in a shear- and buoyancy-driven enclosure has been investigated in this article. The micropolar fluid model is used for the rheological behavior of the non-Newtonian fluid. A heat source with constant volumetric rate is attached in a part of the bottom wall and the remaining parts are thermally insulated. The vertical walls of the cavity are considered to be adiabatic, while the top wall is cooled and moves from left to right with uniform velocity. The thermal conductivity and the dynamic viscosity of the nanofluid are represented by different experimental correlations that are suitable to each nanoparticles. The finite volume method is applied to solve the dimensionless form of the governing equations. A discussion is provided for the effects of the governing parameters on the local Nusselt number and average Nusselt number along the heat source. It is found that an increase in the vortex-viscosity parameter causes a reduction in the local Nusselt number. As the vortex-viscosity parameter increases by 10 times from 0.5 to 5, the Nusselt number reduces by 15%. Additionally, as the nanoparticle volume fraction increases, the rate of heat transfer increases. As the volume fraction increases by 100% from 0.1 to 0.2, the Nusselt number increases by 86%.

Impact of Partial Slip and Heat Source on MHD Mixed Convection Flow of Nanofluid in a Double Lid-Driven Cavity Containing Insulated Obstacle

2020 ◽  
Vol 9 (3) ◽  
pp. 230-241
Author(s):  
M. A. Mansour ◽  
S. Sivasankaran ◽  
A. M. Rashad ◽  
T. Salah ◽  
Hossam A. Nabwey
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Source ◽  
Mixed Convection ◽  
Vertical Wall ◽  
Partial Slip ◽  
Convection Flow ◽  
Uniform Heat Flux ◽  
Mixed Convection Flow ◽  
Left Wall

The current investigation analyzes the effects of partial slip and heat generation on the mixed convection flow with heat transfer in an inclined double lid-driven square cavity containing centered square adiabatic obstacle in the presence of magnetic field. The used cavity is subjected to constant heat flux and filled with Cu-water nanofluid. The top and bottom horizontal walls are thermally insulated and move with uniform velocity while the right vertical wall is maintained at a constant low temperature. A uniform heat flux is located in a part of th left wall of the cavity while the remaining part of this wall is thermally insulated. Finite volume technique is utilized to solve dimensionless governing equations of the problem. The proposed method is validated with the previous published numerical studies which distinctly offer a good agreement. The obtained results show that changing in the heat source length affects much the flow and thermal fields than the position of heat source. The averag Nusselt number decreases when the aspect ratio of the obstacle and heat source length increases. The heat transfer rate behaves nonlinearly with inclination of the cavity.

Effect of Nanofluid on Heat Transfer Enhancement for Mixed Convection Flow Over a Corrugated Surface

2020 ◽  
Vol 45 (4) ◽  
pp. 373-383
Author(s):  
Nepal Chandra Roy ◽  
Sadia Siddiqa
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Nusselt Number ◽  
Mixed Convection ◽  
Local Nusselt Number ◽  
Richardson Number ◽  
Thermal Boundary Layer ◽  
Volume Fraction ◽  
Convection Flow ◽  
Mixed Convection Flow

AbstractA mathematical model for mixed convection flow of a nanofluid along a vertical wavy surface has been studied. Numerical results reveal the effects of the volume fraction of nanoparticles, the axial distribution, the Richardson number, and the amplitude/wavelength ratio on the heat transfer of Al2O3-water nanofluid. By increasing the volume fraction of nanoparticles, the local Nusselt number and the thermal boundary layer increases significantly. In case of \mathrm{Ri}=1.0, the inclusion of 2 % and 5 % nanoparticles in the pure fluid augments the local Nusselt number, measured at the axial position 6.0, by 6.6 % and 16.3 % for a flat plate and by 5.9 % and 14.5 %, and 5.4 % and 13.3 % for the wavy surfaces with an amplitude/wavelength ratio of 0.1 and 0.2, respectively. However, when the Richardson number is increased, the local Nusselt number is found to increase but the thermal boundary layer decreases. For small values of the amplitude/wavelength ratio, the two harmonics pattern of the energy field cannot be detected by the local Nusselt number curve, however the isotherms clearly demonstrate this characteristic. The pressure leads to the first harmonic, and the buoyancy, diffusion, and inertia forces produce the second harmonic.

scholarly journals Numerical Investigation of Mixed Convection and Entropy Generation in a Wavy-Walled Cavity Filled with Nanofluid and Involving a Rotating Cylinder

Entropy ◽  
2018 ◽  
Vol 20 (9) ◽  
pp. 664 ◽  
Author(s):  
Ammar Alsabery ◽  
Muneer Ismael ◽  
Ali Chamkha ◽  
Ishak Hashim
Keyword(s):  
Heat Exchange ◽  
Rayleigh Number ◽  
Heat Source ◽  
Mixed Convection ◽  
Volume Fraction ◽  
Numerical Study ◽  
Rotational Velocity ◽  
Geometrical Parameters ◽  
Galerkin Finite Element ◽  
Vertical Walls

This numerical study considers the mixed convection and the inherent entropy generated in Al 2 O 3 –water nanofluid filling a cavity containing a rotating conductive cylinder. The vertical walls of the cavity are wavy and are cooled isothermally. The horizontal walls are thermally insulated, except for a heat source segment located at the bottom wall. The dimensionless governing equations subject to the selected boundary conditions are solved numerically using the Galerkin finite-element method. The study is accomplished by inspecting different ranges of the physical and geometrical parameters, namely, the Rayleigh number ( 10 3 ≤ R a ≤ 10 6 ), angular rotational velocity ( 0 ≤ Ω ≤ 750 ), number of undulations ( 0 ≤ N ≤ 4 ), volume fraction of Al 2 O 3 nanoparticles ( 0 ≤ ϕ ≤ 0.04 ), and the length of the heat source ( 0.2 ≤ H ≤ 0.8 ) . The results show that the rotation of the cylinder boosts the rate of heat exchange when the Rayleigh number is less than 5 × 10 5 . The number of undulations affects the average Nusselt number for a still cylinder. The rate of heat exchange increases with the volume fraction of the Al 2 O 3 nanoparticles and the length of the heater segment.

scholarly journals Radiative mixed convection flow of maxwell nanofluid over a stretching cylinder with joule heating and heat source/sink effects

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Saeed Islam ◽  
Arshad Khan ◽  
Poom Kumam ◽  
Hussam Alrabaiah ◽  
Zahir Shah ◽  
...  
Keyword(s):  
Brownian Motion ◽  
Heat Source ◽  
Mixed Convection ◽  
Joule Heating ◽  
Internal Heat ◽  
Convection Flow ◽  
Stretching Cylinder ◽  
Mixed Convection Flow ◽  
Maxwell Nanofluid ◽  
Source Sink

Abstract This work analyses thermal effect for a mixed convection flow of Maxwell nanofluid spinning motion produced by rotating and bidirectional stretching cylinder. Impacts of Joule heating and internal heat source/sink are also taken into account for current investigation. Moreover, the flow is exposed to a uniform magnetic field with convective boundary conditions. The modeled equations are converted to set of ODEs through group of similar variables and are then solved by using semi analytical technique HAM. It is observed in this study that, velocity grows up with enhancing values of Maxwell, mixed convection parameters and reduces with growing values of magnetic parameter. Temperature jumps up with increasing values of heat source, Eckert number, Brownian motion,thermophoresis parameter and jumps down with growing values of Prandtl number and heat sink. The concentration is a growing function of thermophoresis parameter and a reducing function of Brownian motion and Schmidt number.

scholarly journals Mixed Convection Flow over an Unsteady Stretching Surface in a Porous Medium with Heat Source

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Syed Muhammad Imran ◽  
Saleem Asghar ◽  
Muhammad Mushtaq
Keyword(s):  
Porous Medium ◽  
Heat Source ◽  
Mixed Convection ◽  
Numerical Solutions ◽  
Saturated Porous Medium ◽  
Convection Flow ◽  
Mixed Convection Flow ◽  
Continuous Increase ◽  
Unsteady Mixed Convection ◽  
Unsteady Stretching Surface

This paper deals with the analysis of an unsteady mixed convection flow of a fluid saturated porous medium adjacent to heated/cooled semi-infinite stretching vertical sheet in the presence of heat source. The unsteadiness in the flow is caused by continuous stretching of the sheet and continuous increase in the surface temperature. We present the analytical and numerical solutions of the problem. The effects of emerging parameters on field quantities are examined and discussed.

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