Mathematical Investigation for Flow Characteristics of Laminar Ferro-Nanofluid Incorporating Cobalt Ferrite Nanoparticles

2021 ◽  
Vol 68 ◽  
pp. 52-69
Author(s):  
Ahmed S. Rashed ◽  
Ehsan H. Nasr ◽  
Magda M. Kassem
Keyword(s):  
Boundary Layer ◽  
Base Fluid ◽  
Cobalt Ferrite ◽  
Volume Fraction ◽  
Flow Characteristics ◽  
Ferrite Nanoparticles ◽  
Group Method ◽  
Governing System ◽  
Mathematical Investigation ◽  
Nanoparticles Volume Fraction

The effect of a magnetic source of variable strength has been studied on ferro-nanofluid incorporating nanoparticles of Cobalt ferrite (CoFe2O4) with water as a base fluid. Group method has been used to remodel the governing system to a system of ordinary differential equations. The recent study was motivated by inspecting the effect of four parameters including nanoparticles volume fraction, , Prandtl number, , magnetic field strength of the source,, and temperature difference ratio with respect to ambient temperature, . The results showed that the nanofluid velocity and shear stress increased as long as and increase. On the other hand, both are inversely related to the increment in Pr and Temperature distribution inside the boundary layer was noticed to increase due to the increment in Pr values and decrease due to the increment ratios. Contrarily, the heat flux throughout the boundary layer decreased and increased due to increasing respectively. Key words: Ferro-hydrodynamic; Nanofluids; Group Method

Study of the boundary layer heat transfer of nanofluids over a stretching sheet: Passive control of nanoparticles at the surface

2015 ◽  
Vol 93 (7) ◽  
pp. 725-733 ◽  
Author(s):  
M. Ghalambaz ◽  
E. Izadpanahi ◽  
A. Noghrehabadi ◽  
A. Chamkha
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Boundary Layer ◽  
Nusselt Number ◽  
Heat Transfer Enhancement ◽  
Base Fluid ◽  
Stretching Sheet ◽  
Volume Fraction ◽  
Enhancement Ratio ◽  
Transfer Enhancement

The boundary layer heat and mass transfer of nanofluids over an isothermal stretching sheet is analyzed using a drift-flux model. The relative slip velocity between the nanoparticles and the base fluid is taken into account. The nanoparticles’ volume fractions at the surface of the sheet are considered to be adjusted passively. The thermal conductivity and the dynamic viscosity of the nanofluid are considered as functions of the local volume fraction of the nanoparticles. A non-dimensional parameter, heat transfer enhancement ratio, is introduced, which shows the alteration of the thermal convective coefficient of the nanofluid compared to the base fluid. The governing partial differential equations are reduced into a set of nonlinear ordinary differential equations using appropriate similarity transformations and then solved numerically using the fourth-order Runge–Kutta and Newton–Raphson methods along with the shooting technique. The effects of six non-dimensional parameters, namely, the Prandtl number of the base fluid Prbf, Lewis number Le, Brownian motion parameter Nb, thermophoresis parameter Nt, variable thermal conductivity parameter Nc and the variable viscosity parameter Nv, on the velocity, temperature, and concentration profiles as well as the reduced Nusselt number and the enhancement ratio are investigated. Finally, case studies for Al2O3 and Cu nanoparticles dispersed in water are performed. It is found that increases in the ambient values of the nanoparticles volume fraction cause decreases in both the dimensionless shear stress f″(0) and the reduced Nusselt number Nur. Furthermore, an augmentation of the ambient value of the volume fraction of nanoparticles results in an increase the heat transfer enhancement ratio hnf/hbf. Therefore, using nanoparticles produces heat transfer enhancement from the sheet.

CFD Investigation of Al2O3 Nanoparticles Effect on Heat Transfer Enhancement of Newtonian and Non-Newtonian Fluids in a Helical Coil

2019 ◽  
Vol 14 (3) ◽  
Author(s):  
Javad Aminian Dehkordi ◽  
Arezou Jafari
Keyword(s):  
Heat Transfer ◽  
Aqueous Solution ◽  
Nusselt Number ◽  
Base Fluid ◽  
Volume Fraction ◽  
Reynolds Numbers ◽  
Helical Coil ◽  
Al2o3 Nanoparticles ◽  
Nanoparticles Volume Fraction ◽  
Computational Fluid Dynamics Cfd

Abstract The present study applied computational fluid dynamics (CFD) to investigate the heat transfer of Newtonian (water) and non-Newtonian (0.3 %wt. aqueous solution of carboxymethylcellulose (CMC)) fluids in the presence of Al2O3 nanoparticles. To analyze the heat transfer rate, investigations were performed in a vertical helical coil as essential heat transfer equipment, at different inlet Reynolds numbers. To verify the accuracy of the simulation model, experimental data reported in the literature were employed. Comparisons showed the validity of simulation results. From the results, compared to the aqueous solution of CMC, water had a higher Nusselt number. In addition, it was observed that adding nanoparticles to a base fluid presented different results in which water/Al2O3 nanofluid with nanoparticles’ volume fraction of 5 % was more effective than the same base fluid with a volume fraction of 10 %. In lower ranges of Reynolds number, adding nanoparticles was more effective. For CMC solution (10 %), increasing concentration of nanoparticles caused an increase in the apparent viscosity. Consequently, the Nusselt number was reduced. The findings reveal the important role of fluid type and nanoparticle concentration in the design and development of heat transfer equipment.

Turbulent forced convection flow of nanofluids over triple forward facing step

2017 ◽  
Vol 14 (4) ◽  
pp. 263-278 ◽  
Author(s):  
Nawar Mohammed Ridha Hashim ◽  
Mohd. Zamri Yusoff ◽  
Hussein Ahmed Mohammed
Keyword(s):  
Heat Transfer ◽  
Base Fluid ◽  
Volume Fraction ◽  
Flow Characteristics ◽  
Convection Flow ◽  
Content Type ◽  
Flow Geometry ◽  
Different Types ◽  
Forced Convection Flow ◽  
Fluid Flow Characteristics

Purpose The purpose of this paper is to numerically study the phenomenon of separation and subsequent reattachment that happens due to a sudden contraction or expansion in flow geometry, in addition, to investigating the effect of nanoparticles suspended in water on heat transfer enhancement and fluid flow characteristics. Design/methodology/approach Turbulent forced convection flow over triple forward facing step (FFS) in a duct is numerically studied by using different types of nanofluids. Finite volume method is employed to carry out the numerical investigations. with nanoparticles volume fraction in the range of 1-4 per cent and nanoparticles diameter in the range 30-75 nm, suspended in water. Several parameters were studied, such as the geometrical specification (different step heights), boundary conditions (different Reynolds [Re] numbers), types of fluids (base fluid with different types of nanoparticles), nanoparticle concentration (different volume fractions) and nanoparticle size. Findings The numerical results indicate that the Nusselt number increases as the volume fraction increases, but it decreases as the diameter of the nanoparticles of nanofluids increases. The turbulent kinetic energy and its dissipation rate increase as Re number increases. The velocity magnitude increases as the density of nanofluids decreases. No significant effect of increasing the three steps heights on Nusselt along the heated wall, except in front of first step where increasing the first step height leads to an increase in the recirculation zone size adjacent to it. Research limitations/implications The phenomenon of separation and subsequent reattachment happened due to a sudden contraction or expansion in flow geometry, such as forward facing and backward facing steps, respectively, can be recognized in many engineering applications where heat transfer enhancement is required. Some examples include cooling systems for electronic equipment, heat exchanger, diffusers and chemical process. Understanding the concept of these devices is very important from the engineering point of view. Originality/value Convective heat transfer can be enhanced passively by changing flow geometry, boundary conditions, the traditional fluids or by enhancing thermal conductivity of the fluid. Great attention has been paid to increase the thermal conductivity of base fluid by suspending nano-, micro- or larger-sized particles in fluid. The products from suspending these particles in the base fluid are called nanofluids. Many studies have been conducted to investigate the heat transfer and fluid flow characteristics over FFS. This study is the first where nanofluids are employed as working fluids for flow over triple FFS.

MHD Marangoni boundary layer problem for hybrid nanofluids with thermal radiation

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Emad H. Aly ◽  
Abdelhalim Ebaid
Keyword(s):  
Magnetic Field ◽  
Boundary Layer ◽  
Copper Nanoparticles ◽  
Volume Fraction ◽  
Content Type ◽  
Boundary Layer Problem ◽  
Nanoparticles Volume Fraction ◽  
Hybrid Nanofluids ◽  
Marangoni Boundary Layer ◽  
Layer Problem

Purpose The purpose of this paper is to study flow of the Marangoni boundary layer pasta surface embedded in a porous medium saturated by a hybrid nanofluid in the presence of a magnetic field and thermal radiation. Design/methodology/approach The governing model was converted into ordinary differential equations applying proper similarity transformations. Therefore, Laplace transform was used to exactly solve the resulted equations. Hence, the influence of the velocity profile and temperature distribution was investigated under impacts of the involved parameters. Findings In the case of regular fluid, i.e. the solid volume fractions are zeros, the current results are in a very good agreement with those in the literature. It was found that the velocity decreases (increases) on increasing the parameters of copper-nanoparticles volume fraction, magnetic field and suction (permeability and injection). Further, the temperature increases (decreases) with an increase of the copper-nanoparticles volume fraction, magnetic field, injection and radiation (permeability and suction). Originality/value The current results of the Marangoni boundary layer problem for hybrid nanofluids are new, original and extend the previous problems investigated by many authors for the case of regular/nano fluids.

scholarly journals g-Jitter Free Convection Flow of Nanofluid in The Three-Dimensional Stagnation Point Region

MATEMATIKA ◽  
2019 ◽  
Vol 35 (2) ◽  
pp. 260-270 ◽  
Author(s):  
Mohamad Hidayad Ahmad Kamal ◽  
Anati Ali ◽  
Sharidan Shafie
Keyword(s):  
Boundary Layer ◽  
Free Convection ◽  
Skin Friction ◽  
Stagnation Point ◽  
Volume Fraction ◽  
Nodal Point ◽  
Boundary Layer Equation ◽  
Three Dimensional ◽  
Aluminium Oxide ◽  
Nanoparticles Volume Fraction

The three dimensional free convection boundary layer flow near a stagnation point region is embedded in viscous nanofluid with the effect of g-jitter is studied in this paper. Copper (Cu) and aluminium oxide (Al2O3) types of water base nanofluid are cho- sen with the constant Prandtl number, Pr=6.2. Based on Tiwari-Das nanofluid model, the boundary layer equation used is converted into a non-dimensional form by adopting non- dimensional variables and is solved numerically by engaging an implicit finite-difference scheme known as Keller-box method. Behaviors of fluid flow such as skin friction and Nusset number are studied by the controlled parameters including oscillation frequency, amplitude of gravity modulation and nanoparticles volume fraction. The reduced skin friction and Nusset number are presented graphically and discussed for different values of principal curvatures ratio at the nodal point. The numerical results shows that, in- crement occurs in the values of Nusset number with the presence of solid nanoparticles together with the values of the skin friction. It is worth mentioning that for the plane stagnation point there is an absence of reduced skin friction along the y-direction where as for axisymmetric stagnation point, the reduced skin friction for both directions are the same. As nanoparticles volume fraction increased, the skin friction increased as well as the Nusset number. The results, indicated that skin frictions of copper are found higher than aluminium oxide.

scholarly journals Non-Uniform Magnetic Field Effects on Ferrofluids Film Boiling: A Numerical Study

2020 ◽  
Author(s):  
Rasool Maroofiazar ◽  
Seyyede Fatemeh Haghgoo
Keyword(s):  
Magnetic Field ◽  
Base Fluid ◽  
Uniform Magnetic Field ◽  
Volume Fraction ◽  
Numerical Study ◽  
Film Boiling ◽  
Vapor Film ◽  
Magnetic Field Effects ◽  
Nanoparticles Volume Fraction ◽  
Film Characteristics

In this paper the effect of magnetic field on film boiling of ferrofluids on a horizontal flat plate has been investigated. The obtained results indicate that adding nanoparticles into the base fluid changes vapor film characteristics mainly due to changes in thermophysical properties of the base fluid. Also, ferrofluids enhances film boiling heat transfer on horizontal plate specially at higher volume concentration of nanoparticles. Another important result of this study is the effect of non-uniform magnetic field on horizontal film boiling characteristics. Application of magnetic field changes vapor film behavior mostly at higher values of magnetic field intensity (400) and nanoparticles volume fraction (4 percent).

scholarly journals Radiation effects on 3D rotating flow of Cu-water nanoliquid with viscous heating and prescribed heat flux using modified Buongiorno model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wahib Owhaib ◽  
Mahanthesh Basavarajappa ◽  
Wael Al-Kouz
Keyword(s):  
Boundary Layer ◽  
Heat Flux ◽  
Layer Thickness ◽  
Radiation Effects ◽  
Volume Fraction ◽  
Layer Structure ◽  
Three Dimensional ◽  
Nanoparticles Volume Fraction ◽  
Thermal Layer ◽  
Buongiorno Model

AbstractIn this article, the three-dimensional (3D) flow and heat transport of viscous dissipating Cu-H2O nanoliquid over an elongated plate in a rotating frame of reference is studied by considering the modified Buongiorno model. The mechanisms of haphazard motion and thermo-migration of nanoparticles along with effective nanoliquid properties are comprised in the modified Buongiorno model (MBM). The Rosseland radiative heat flux and prescribed heat flux at the boundary are accounted. The governing nonlinear problem subjected to Prandtl’s boundary layer approximation is solved numerically. The consequence of dimensionless parameters on the velocities, temperature, and nanoparticles volume fraction profiles is analyzed via graphical representations. The temperature of the base liquid is improved significantly owing to the existence of copper nanoparticles in it. The phenomenon of rotation improves the structure of the thermal boundary layer, while, the momentum layer thickness gets reduced. The thermal layer structure gets enhanced due to the Brownian movement and thermo-migration of nanoparticles. Moreover, it is shown that temperature enhances owing to the presence of thermal radiation. In addition, it is revealed that the haphazard motion of nanoparticles decays the nanoparticle volume fraction layer thickness. Also, the skin friction coefficients found to have a similar trend for larger values of rotation parameter. Furthermore, the results of the single-phase nanoliquid model are limiting the case of this study.

Unsteady Boundary Layer Flow of Nanofluid Past an Impulsively Stretching Sheet

2013 ◽  
Vol 29 (3) ◽  
pp. 423-432 ◽  
Author(s):  
M. Mustafa ◽  
T. Hayat ◽  
A. Alsaedi
Keyword(s):  
Boundary Layer ◽  
Brownian Motion ◽  
Boundary Layer Flow ◽  
Stretching Sheet ◽  
Volume Fraction ◽  
Similarity Transformations ◽  
Nanoparticles Concentration ◽  
Motion Effect ◽  
Nanoparticles Volume Fraction ◽  
Layer Flow

AbstractThe unsteady laminar boundary layer flow of nanofluid caused by a linearly stretching sheet is considered. Transport equations contain the simultaneous effects of Brownian motion and thermophoretic diffusion of nanoparticles. The relevant partial differential equations are non-dimensionalized and transformed into similar forms by using appropriate similarity transformations. The uniformly valid explicit expressions of velocity, temperature and nanoparticles volume fraction are derived. Convergence of the series solutions is carefully analyzed. It is observed that an increase in the strength of Brownian motion effect rises the temperature appreciably. However rate of heat transfer and nanoparticles concentration at the sheet is reduced when Brownian motion effect intensifies. It is also found that the temperature and nanoparticles concentration are increasing functions of the unsteady parameter.

scholarly journals Analysis of Platelet Shape Al2O3 and TiO2 on Heat Generative Hydromagnetic Nanofluids for the Base Fluid C2H6O2 in a Vertical Channel of Porous Medium

2021 ◽  
Vol 18 (14) ◽  
Author(s):  
Silpi HAZARIKA ◽  
Sahin AHMED ◽  
Ali J. CHAMKHA
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Porous Medium ◽  
Heat Generation ◽  
Base Fluid ◽  
Volume Fraction ◽  
Metal Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Nanoparticles Volume Fraction ◽  
Platelet Shape

An analytical investigation is performed on the unsteady hydromagnetic flow of nanoparticles Al2O3 and TiO2 in the EG base fluid through a saturated porous medium bounded by two vertical surfaces with heat generation and no-slip boundary conditions. The physics of initial and boundary conditions is designated with the flow model's non-linear partial differential equations. The analytical expressions of nanofluid velocity and temperature with the channel are derived, and Matlab Codes are used to plot the significant results for physical variables. From the physical point of view for nanofluid velocity and temperature results, the base fluid C2H6O2 has a higher viscosity and thermal conductivity than that of water. Physically, the platelet shape Al2O3 nanofluid has the highest velocity than TiO2 nanofluid. It is found that the velocity of nanofluid enhanced the porosity and nanoparticles volume fraction for Al2O3 - EG and TiO2 - EG base nanofluids. However, this trend is reversed for the effects of heat generation. Obtained results indicate that an increase in nanoparticles volume fraction raises the skin friction near the surface, but profiles gradually become linear, due to less frictional effects of nanoparticles. Moreover, due to higher values of nanoparticles volume fraction, the thermal conductivity is raised, and thus the thickness of the thermal boundary layer is declined. The results show that the method provides excellent approximations to the analytical solution of nonlinear system with high accuracy. Metal oxide nanoparticles have wide applications in various fields due to their small sizes, such as the pharmaceutical industry and biomedical engineering. HIGHLIGHTS Impact of platelet shape Al2O3 and TiO2 for base fluid C2H6O2 is studied In Couette and Poiseuille flow, nanoparticles play a vital role to enhance the heat transfer The infinite series solution has been used for solving the non-linear PDE’s The uses of Al2O3 and TiO2 in significant heat transfer applications is overviewed The physiochemical and structural features of metal oxide nanoparticles have diverse biomedical applications GRAPHICAL ABSTRACT

scholarly journals Enhanced Heat Transfer for NePCM-Melting-Based Thermal Energy of Finned Heat Pipe

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 129
Author(s):  
Sameh E. Ahmed ◽  
Aissa Abderrahmane ◽  
Sorour Alotaibi ◽  
Obai Younis ◽  
Radwan A. Almasri ◽  
...  
Keyword(s):  
Energy Storage ◽  
Phase Change Materials ◽  
Volume Fraction ◽  
Liquid Fraction ◽  
Melting Process ◽  
Flow Structures ◽  
The Finite Element Method ◽  
Flow Area ◽  
Governing System ◽  
Nanoparticles Volume Fraction

Using phase change materials (PCMs) in energy storage systems provides various advantages such as energy storage at a nearly constant temperature and higher energy density. In this study, we aimed to conduct a numerical simulation for augmenting a PCM’s melting performance within multiple tubes, including branched fins. The suspension contained Al2O3/n-octadecane paraffin, and four cases were considered based on a number of heated fins. A numerical algorithm based on the finite element method (FEM) was applied to solve the dimensionless governing system. The average liquid fraction was computed over the considered flow area. The key parameters are the time parameter (100 ≤t≤600 s) and the nanoparticles’ volume fraction (0%≤φ≤8%). The major outcomes revealed that the flow structures, the irreversibility of the system, and the melting process can be controlled by increasing/decreasing number of the heated fins. Additionally, case four, in which eight heated fins were considered, produced the largest average liquid fraction values.

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