scholarly journals Numerical Solution of Biomagnetic Power-Law Fluid Flow and Heat Transfer in a Channel

Symmetry ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1959
Author(s):  
Adrian S. Halifi ◽  
Sharidan Shafie ◽  
Norsarahaida S. Amin
Keyword(s):  
Heat Transfer ◽  
Shear Stress ◽  
Power Law ◽  
Vortex Formation ◽  
Shear Thickening ◽  
Power Law Model ◽  
Governing Equations ◽  
Power Law Fluid ◽  
Transfer Parameters ◽  
Power Law Index

The effect of non-Newtonian biomagnetic power-law fluid in a channel undergoing external localised magnetic fields is investigated. The governing equations are derived by considering both effects of Ferrohydrodynamics (FHD) and Magnetohydrodynamics (MHD). These governing equations are difficult to solve due to the inclusion of source term from magnetic equation and the nonlinearity of the power-law model. Numerical scheme of Constrained Interpolation Profile (CIP) is developed to solve the governing equations numerically. Extensive results carried out show that this method is efficient on studying the biomagnetic and non-Newtonian power-law flow. New results show that the inclusion of power-law model affects the vortex formation, skin friction and heat transfer parameter significantly. Regardless of the power-law index, the vortex formation length increases when Magnetic number increases. The effect of this vortex however decreases with the inclusion of power-law where in the shear thinning case, the arising vortex is more pronounced than in the shear thickening case. Furthermore, increasing of power-law index from shear thinning to shear thickening, decreases the wall shear stress and heat transfer parameters. However for high Magnetic number, the wall shear stress and heat transfer parameters increase especially near the location of the magnetic source. The results can be used as a guide on assessing the potential effects of radiofrequency fields (RF) from electromagnetic fields (EMF) exposure on blood vessel.

Developing and Fully Developed Non-Newtonian Fluid Flow and Heat Transfer Through Concentric Annuli

2013 ◽  
Vol 135 (7) ◽  
Author(s):  
Mohammad Sefid ◽  
Ehsan Izadpanah
Keyword(s):  
Heat Transfer ◽  
Power Law ◽  
Convection Heat Transfer ◽  
Channel Length ◽  
Laminar Flows ◽  
Rheological Parameter ◽  
Power Law Fluid ◽  
Thermal Boundary Conditions ◽  
Flow And Heat Transfer ◽  
Power Law Index

Developing and fully developed laminar flows of power law fluid with forced convection heat transfer through a concentric annular duct are numerically analyzed. The results are presented for the following ranges: 0.2 ≤ n ≤ 1.8 (power law index), 10 ≤ Re ≤ 1000 (Reynolds number), and r* = 0.2, 0.5, 0.8 (aspect ratio). In addition, the influences of different thermal boundary conditions on the thermal performance are delineated. The effects of rheological parameter on the developing length, friction factor, temperature distribution, velocity profile, and Nusselt number along the channel length are investigated. The results are compared with earlier research and excellent agreement was observed.

scholarly journals Slip-Flow and Heat Transfer in a Porous Microchannel Saturated with Power-Law Fluid

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Yazan Taamneh ◽  
Reyad Omari
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Skin Friction ◽  
Knudsen Number ◽  
Power Law ◽  
Slip Flow ◽  
Darcy Number ◽  
Power Law Fluid ◽  
Flow And Heat Transfer ◽  
Power Law Index

This study aims to numerically examine the fluid flow and heat transfer in a porous microchannel saturated with power-law fluid. The governing momentum and energy equations are solved by using the finite difference technique. The present study focuses on the slip flow regime, and the flow in porous media is modeled using the modified Darcy-Brinkman-Forchheimer model for power-law fluids. Parametric studies are conducted to examine the effects of Knudsen number, Darcy number, power law index, and inertia parameter. Results are given in terms of skin friction and Nusselt number. It is found that when the Knudsen number and the power law index decrease, the skin friction on the walls decreases. This effect is reduced slowly while the Darcy number decreases until it reaches the Darcy regime. Consequently, with a very low permeability the effect of power law index vanishes. The numerical results indicated also that when the power law index decreases the fully-developed Nusselt number increases considerably especially, in the limit of high permeability, that is, nonDarcy regime. As far as Darcy regime is concerned the effects of the Knudsen number and the power law index of the fully-developed Nusselt number is very little.

Surface Instabilities on a Thin Power-Law Fluid During Spin Coating

2014 ◽  
Vol 30 (5) ◽  
pp. 505-513 ◽  
Author(s):  
C.-I. Chen ◽  
M.-C. Lin ◽  
C.-K. Chen
Keyword(s):  
Power Law ◽  
Spin Coating ◽  
Film Flow ◽  
Stokes Equations ◽  
Multiple Scales ◽  
Landau Equation ◽  
Shear Thickening ◽  
Vital Role ◽  
Power Law Fluid ◽  
Power Law Index

AbstractThe phenomena of surface instabilities in a thin power-law fluid during spin coating are investigated. The set of Navier-Stokes equations with non-Newtonian behavior in the region of low Reynolds number serves as a mathematical description of the physical systems. Long-wave perturbation analysis is proposed to derive an evolution equation of the Ostwald de-Waele type fluid to govern the propagation of surface waves. Weakly nonlinear dynamics of film flow is studied by the multiple scales method. The amplitude of instability is determined by a Ginzburg-Landau equation. The study reveals that the degree of power-law index plays a vital role in stabilizing the film flow. The shear-thinning fluid is more unstable than the shear-thickening fluid in the stability analysis. Further, the nonlinear wave speed in the supercritical stability region decreases with increasing values of power-law index.

scholarly journals Steady flow of a power law fluid through a tapered non-symmetric stenotic tube

2019 ◽  
Vol 4 (1) ◽  
pp. 255-266 ◽  
Author(s):  
Riaz Ahmad ◽  
Asma Farooqi ◽  
Jiazhong Zhang ◽  
Nasir Ali
Keyword(s):  
Exact Solution ◽  
Shear Stress ◽  
Steady Flow ◽  
Power Law ◽  
Governing Equation ◽  
Axial Velocity ◽  
Shear Thickening ◽  
Power Law Fluid ◽  
Shear Thickening Fluid ◽  
Parameters Of Interest

AbstractA steady flow of a power law fluid through an artery with a stenosis has been analyzed. The equation governing the flow is derived under the assumption of mild stenosis. An exact solution of the governing equation is obtained, which is then used to study the effects of various parameters of interest on axial velocity, resistance to flow and shear stress distribution. It is found that axial velocity increases while resistance to flow decreases when going from shear-thinning to shear-thickening fluid. Moreover, the magnitude of shear stress decreases by increasing the tapering parameter. This problem was already addressed by Nadeem et al. [14], but the results presented by them were erroneous due to a mistake in the derivation of the governing equation of the flow. This mistake is highlighted in the "Formulation of the Problem" section.

Power-Law Fluid Flow Passing Two Square Cylinders in Tandem Arrangement

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Izadpanah Ehsan ◽  
Sefid Mohammad ◽  
Nazari Mohammad Reza ◽  
Jafarizade Ali ◽  
Ebrahim Sharifi Tashnizi
Keyword(s):  
Reynolds Number ◽  
Power Law ◽  
Shear Thickening ◽  
Shear Thinning ◽  
Newtonian Fluids ◽  
Power Law Fluid ◽  
Tandem Arrangement ◽  
Square Cylinders ◽  
Shear Thickening Fluids ◽  
Power Law Index

Two-dimensional laminar flow of a power-law fluid passing two square cylinders in a tandem arrangement is numerically investigated in the ranges of 1< Re< 200 and 1 ≤ G ≤ 9. The fluid viscosity power-law index lies in the range 0.5 ≤ n ≤ 1.8, which covers shear-thinning, Newtonian and shear-thickening fluids. A finite volume code based on the SIMPLEC algorithm with nonstaggered grid is used. In order to discretize the convective and diffusive terms, the third order QUICK and the second-order central difference scheme are used, respectively. The influence of the power-law index, Reynolds number and gap ratio on the drag coefficient, Strouhal number and streamlines are investigated, and the results are compared with other studies in the literature to validate the methodology. The effect of the time integration scheme on accuracy and computational time is also analyzed. In the ranges of Reynolds number and power-law index studied here, vortex shedding is known to occur for square cylinders in tandem. This study represents the first systematic investigation of this phenomenon for non-Newtonian fluids in the open literature. In comparison to Newtonian fluids, it is found that the onset of leading edge separation occurs at lower Reynolds number for shear-thinning fluids and is delayed to larger values for shear-thickening fluids.

scholarly journals A new model for flow and heat of a power law fluid in a pipe

2011 ◽  
Vol 15 (suppl. 1) ◽  
pp. 127-130 ◽  
Author(s):  
Botong Li ◽  
Liancun Zheng ◽  
Xinxin Zhang
Keyword(s):  
Heat Transfer ◽  
Power Law ◽  
Control Volume ◽  
Fluid Viscosity ◽  
Power Law Fluid ◽  
Viscous Boundary Layer ◽  
New Model ◽  
Viscous Boundary ◽  
S Model ◽  
Power Law Index

In this paper, a new model is proposed for flow and heat transfer of a power law fluid in a pipe. The flow is hydro-dynamically fully-developed and laminar while the characteristic of the fluid viscosity changes with the entrance distance considered. We assume that the power-law index is no longer a constant but a function of the entrance distance. Also, in terms of analogy between the viscous boundary layer and the thermal one, the thermal diffusion coefficient is considered as a power-law function of temperature gradient as Zheng?s model. A control volume technique based on the finite difference model coupled with the LU decomposition method is adopted and the least squares polynomial is used to approximate the non-linear item. The results show that the heat transfer behavior strongly depend on the value of the power law index.

scholarly journals A study of heat transfer in power law nanofluid

2016 ◽  
Vol 20 (6) ◽  
pp. 2015-2026 ◽  
Author(s):  
Rahmat Ellahi ◽  
Mohsin Hassan ◽  
Ahmad Zeeshan
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Shear Stress ◽  
Power Law ◽  
Base Fluid ◽  
Convection Flow ◽  
Mixed Convection Flow ◽  
Power Law Fluid ◽  
Power Law Nanofluid ◽  
Shear Thinning Fluid

The purpose of this paper is to study the effects of nanoparticles on mixed convection flow of power law fluid. The shear thinning fluid is considered as base fluid. The nanoparticles of copper for nanofluid are taken into account. To analysis the flow and temperature behavior, various mass concentrations of polyvinyl alcohol in water, different sizes and concentrations of nanoparticles are used. The effects of nanoparticle concentrations on shear stress, heat flux and thermal resistance are also presented.

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.

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