Coupled flow and heat transfer of power-law Nanofluids on a non-isothermal rough rotary disk subject to magnetic field

2021 ◽  
Author(s):  
Yunxian Pei ◽  
Xuelan Zhang ◽  
Liancun Zheng ◽  
Xinzi Wang
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Power Law ◽  
Numerical Solutions ◽  
Volume Fraction ◽  
Rotating Disk ◽  
Coupled Flow ◽  
Friction Coefficients ◽  
Nanoparticle Shape ◽  
Flow And Heat Transfer

Abstract In this paper, we study coupled flow and heat transfer of power-law nanofluids on a non-isothermal rough rotating disk subject to a magnetic field. The problem is formulated in terms of specified curvilinear orthogonal coordinate system. An improved BVP4C algorithm is proposed and numerical solutions are obtained. The influence of volume fraction, types and shapes of nanoparticles, magnetic field and power-law index on the flow and heat transfer behavior are discussed.<br/>Results show that the power-law exponents (PLE), nanoparticle volume fraction (NVF) and magnetic field inclination angle (MFIA) are almost no effects on velocities in wave surface direction, but have small or significant effects on azimuth direction. NVF have remarkable influence on local Nusselt number (LNN) and friction coefficients (FC) in radial and azimuth directions (AD). LNN increases with NVF while FC in AD decrease. The types of nanoparticles, magnetic field strength and inclination have small effects on LNN, but they have remarkable effects on the friction coefficients with positively correlated while the inclination is negatively correlated with heat transfer rate. The size of the nanoparticle shape factor is positively correlated with LNN.

scholarly journals Jet Impingement Heat Transfer of Confined Single and Double Jets with Non-Newtonian Power Law Nanofluid under the Inclined Magnetic Field Effects for a Partly Curved Heated Wall

2021 ◽  
Vol 13 (9) ◽  
pp. 5086
Author(s):  
Fatih Selimefendigil ◽  
Hakan F. Oztop ◽  
Ali J. Chamkha
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Particle Size ◽  
Aspect Ratio ◽  
Power Law ◽  
Volume Fraction ◽  
Inclined Magnetic Field ◽  
Magnetic Field Effects ◽  
Power Law Nanofluid ◽  
Power Law Index

Single and double impinging jets heat transfer of non-Newtonian power law nanofluid on a partly curved surface under the inclined magnetic field effects is analyzed with finite element method. The numerical work is performed for various values of Reynolds number (Re, between 100 and 300), Hartmann number (Ha, between 0 and 10), magnetic field inclination (γ, between 0 and 90), curved wall aspect ratio (AR, between 01. and 1.2), power law index (n, between 0.8 and 1.2), nanoparticle volume fraction (ϕ, between 0 and 0.04) and particle size in nm (dp, between 20 and 80). The amount of rise in average Nusselt (Nu) number with Re number depends upon the power law index while the discrepancy between the Newtonian fluid case becomes higher with higher values of power law indices. As compared to case with n = 1, discrepancy in the average Nu number are obtained as −38% and 71.5% for cases with n = 0.8 and n = 1.2. The magnetic field strength and inclination can be used to control the size and number or vortices. As magnetic field is imposed at the higher strength, the average Nu reduces by about 26.6% and 7.5% for single and double jets with n greater than 1 while it increases by about 4.78% and 12.58% with n less than 1. The inclination of magnetic field also plays an important role on the amount of enhancement in the average Nu number for different n values. The aspect ratio of the curved wall affects the flow field slightly while the average Nu variation becomes 5%. Average Nu number increases with higher solid particle volume fraction and with smaller particle size. At the highest particle size, it is increased by about 14%. There is 7% variation in the average Nu number when cases with lowest and highest particle size are compared. Finally, convective heat transfer performance modeling with four inputs and one output is successfully obtained by using Adaptive Neuro-Fuzzy Interface System (ANFIS) which provides fast and accurate prediction results.

scholarly journals Flow and Heat Transfer at a Nonlinearly Shrinking Porous Sheet:The Case of Asymptotically Large Powerlaw Shrinking Rates

2013 ◽  
Vol 18 (3) ◽  
pp. 779-791 ◽  
Author(s):  
K.V. Prasad ◽  
K. Vajravelu ◽  
I. Pop
Keyword(s):  
Heat Transfer ◽  
Differential Equations ◽  
Power Law ◽  
Numerical Solutions ◽  
Skin Friction Coefficient ◽  
Temperature Fields ◽  
Shrinking Sheet ◽  
Arbitrary Power ◽  
Keller Box Method ◽  
Flow And Heat Transfer

Abstract The boundary layer flow and heat transfer of a viscous fluid over a nonlinear permeable shrinking sheet in a thermally stratified environment is considered. The sheet is assumed to shrink in its own plane with an arbitrary power-law velocity proportional to the distance from the stagnation point. The governing differential equations are first transformed into ordinary differential equations by introducing a new similarity transformation. This is different from the transform commonly used in the literature in that it permits numerical solutions even for asymptotically large values of the power-law index, m. The coupled non-linear boundary value problem is solved numerically by an implicit finite difference scheme known as the Keller- Box method. Numerical computations are performed for a wide variety of power-law parameters (1 < m < 100,000) so as to capture the effects of the thermally stratified environment on the velocity and temperature fields. The numerical solutions are presented through a number of graphs and tables. Numerical results for the skin-friction coefficient and the Nusselt number are tabulated for various values of the pertinent parameters.

On the Effectiveness of Ion Slip on Steady MHD Flow and Heat Transfer Above a Rotating Disk With Ohmic Heating

2006 ◽  
Vol 128 (6) ◽  
pp. 1236-1239 ◽  
Author(s):  
Hazem Ali Attia
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Steady Flow ◽  
Finite Differences ◽  
Ohmic Heating ◽  
Mhd Flow ◽  
Rotating Disk ◽  
Flow And Heat Transfer ◽  
Ion Slip ◽  
Steady Magnetic Field

The steady flow and heat transfer of a conducting fluid due to the rotation of an infinite, nonconducting disk in the presence of an axial uniform steady magnetic field are studied considering the ion slip and the Ohmic heating. The relevant equations are solved numerically using finite differences and the solution shows that the inclusion of the ion slip gives some interesting results.

scholarly journals Effect of magnetic field on the steady nanofluid flow past obstacle

2021 ◽  
Vol 22 (3) ◽  
pp. 535-542
Author(s):  
Yacine Khelili ◽  
Rafik Bouakkaz
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Laminar Flow ◽  
Hartmann Number ◽  
Volume Fraction ◽  
Transverse Magnetic ◽  
Heated Wall ◽  
Cylinder Wake ◽  
Flow And Heat Transfer ◽  
Model Transition

The fluid flow and heat transfer of a nanofluid past a circular cylinder in a rectangular duct under a strong transverse magnetic field is studied numerically using a quasitwo-dimensional model. Transition from laminar flow with separation to creeping laminar flow is determined as a function of Hartmann number and the volume fraction of nanoparticle, as are critical Hartmann number, and the heat transfer from the heated wall to the fluid. Downstream cross-stream mixing induced by the cylinder wake was found to increase heat transfer. The successive changes in the flow pattern are studied as a function of the Hartmann number. Suppression of vortex shedding occurs as the Hartmann number increases.

scholarly journals Flow and heat transfer of MHD graphene oxide-water nanofluid between two non-parallel walls

2017 ◽  
Vol 21 (5) ◽  
pp. 2095-2104 ◽  
Author(s):  
Mohammadreza Azimi ◽  
Rouzbeh Riazi
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Graphene Oxide ◽  
Volume Fraction ◽  
Flow And Heat Transfer ◽  
S Parameter ◽  
Non Linear ◽  
Optimal Homotopy Asymptotic Method ◽  
Prandtl Numbers ◽  
Linear Differential

The steady 2-D heat transfer and flow between two non-parallel walls of a graphene oxide nanofluid in presence of uniform magnetic field are investigated in this paper. The analytical solution of the non-linear problem is obtained by Galerkin optimal homotopy asymptotic method. At first a similarity transformation is used to reduce the partial differential equations modeling the flow and heat transfer to ordinary non-linear differential equation systems containing the semi angle between the plate?s parameter, Reynolds number, the magnetic field strength, nanoparticle volume fraction, Eckert and Prandtl numbers. Finally, the obtained analytical results have been compared with results achieved from previous works in some cases.

Coupling Effects of Viscous Sheet and Ambient Fluid on Boundary Layer Flow and Heat Transfer in Power-Law Fluids

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Xiaochuan Liu ◽  
Liancun Zheng ◽  
Goong Chen ◽  
Lianxi Ma
Keyword(s):  
Heat Transfer ◽  
Power Law ◽  
Numerical Solutions ◽  
Skin Friction Coefficient ◽  
Similarity Solutions ◽  
Temperature Fields ◽  
Ambient Fluid ◽  
Local Skin ◽  
Flow And Heat Transfer ◽  
Power Law Fluids

This paper investigates the flow and heat transfer of power-law fluids over a stretching sheet where the coupling dynamics influence of viscous sheet and ambient fluid is taken into account via the stress balance. A modified Fourier's law is introduced in which the effects of viscous dissipation are taken into account by assuming that the thermal conductivity is to be shear-dependent on the velocity gradient. The conditions for both velocity and thermal boundary layers admitting similarity solutions are found, and numerical solutions are computed by a Bvp4c program. The results show that the viscous sheet and rheological properties of ambient fluids have significantly influences on both velocity and temperature fields characteristics. The formation of sheet varies with the viscosity of fluid and draw ratio, which then strongly affects the relations of the local skin friction coefficient, the local Nusselt number, and the generalized Reynolds number. Moreover, for specified parameters, the flow and heat transfer behaviors are discussed in detail.

Flow and Heat Transfer of Nanofluids near a Rotating Disk

2013 ◽  
Vol 664 ◽  
pp. 859-865
Author(s):  
I Chung Liu ◽  
Hung Hsun Wang ◽  
Chia Nan Liu
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Volume Fraction ◽  
Rotating Disk ◽  
Thermal Boundary Layer Thickness ◽  
Flow And Heat Transfer ◽  
Rotating Surface ◽  
Layer Flow ◽  
Surface Increase ◽  
Momentum Boundary Layer

The study of boundary layer flow and heat transfer near a rotating disk with nanofluids is investigated numerically. Three types of nanoparticles, namely, silver Ag, copper Cu and alumina Al2O3with water as the base fluid are considered. The results show that the momentum boundary layer thicknesses shortens as the nanoparticle volume fraction increases, whereas thermal boundary layer thickness elongates for increasing ϕ. It is found that the reduced skin-friction coefficients and heat transfer rateat the rotating surface increase linearly with nanoparticle volume fractionϕ. The surface heat transfer rate for Cu-water nanofluid is higher than those of the otherswhen ϕ>0.02, even though the nanoparticle Ag has higher thermal conductivity than that of copper Cu.

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