A Study on Hydromagnetic Pulsating Flow of a Nanofluid in a Porous Channel With Thermal Radiation

2016 ◽  
Vol 33 (2) ◽  
pp. 213-224 ◽  
Author(s):  
A. Vijayalakshmi ◽  
S. Srinivas
Keyword(s):  
Heat Transfer ◽  
Titanium Dioxide ◽  
Thermal Radiation ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Volume Fraction ◽  
Porous Channel ◽  
Nanoparticle Volume Fraction ◽  
Governing Equations ◽  
Nanofluid Flow

AbstractThe present study investigates the hydromagnetic pulsating nanofluid flow in a porous channel with thermal radiation. In this work, we considered water as the base fluid and silver (Ag), copper (Cu), alumina (Al2O3) and titanium dioxide (TiO2) as nanoparticles. The Maxwell-Garnetts and Brinkman models are used to evaluate the effective thermal conductivity and viscosity of the nanofluid. The governing equations are solved analytically and the influence of various parameters on velocity, temperature and heat transfer rate has been discussed through graphical results. From the results, it is found that the rate of heat transfer enhances with an increase of nanoparticle volume fraction. Further, the heat transfer rate is higher for silver nanoparticles as compared with copper, alumina and titanium dioxide.

Flow and Heat Transfer of Gold-Blood Nanofluid in a Porous Channel with Moving/Stationary Walls

2016 ◽  
Vol 33 (3) ◽  
pp. 395-404 ◽  
Author(s):  
S. Srinivas ◽  
A. Vijayalakshmi ◽  
A. Subramanyam Reddy
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Analytical Solutions ◽  
Transfer Rate ◽  
Numerical Solutions ◽  
Volume Fraction ◽  
Porous Channel ◽  
Nanoparticle Volume Fraction ◽  
Similarity Transformations ◽  
Flow And Heat Transfer

AbstractThe present study investigates the flow and heat transfer characteristics of blood carrying gold nanoparticles in a porous channel with moving/stationary walls in the presence of thermal radiation. Blood is considered as Newtonian fluid which is the base fluid and gold (Au) as nanoparticles. The governing equations are transformed into system of ordinary differential equations by using similarity transformations. The analytical solutions are obtained for the flow variables by employing homotopy analysis method (HAM). The analytical solutions are compared with the numerical solutions which are obtained by shooting technique along with Runge-Kutta scheme. It was noticed that there is a good agreement between analytical and numerical results. The influence of various parameters on velocity, temperature and heat transfer rate of gold-blood nanofluid has been discussed in detail. The temperature of the nanofluid increases with increasing the nanoparticle volume fraction. The heat transfer rate at the top wall increases with increasing nanoparticle volume fraction while it decreases for a given increase in radiation parameter.

Effects of NP Shapes on Non-Newtonian Bio-Nanofluid Flow in Suction/Blowing Process with Convective Condition: Sisko Model

2020 ◽  
Vol 45 (2) ◽  
pp. 97-108 ◽  
Author(s):  
Mohamed R. Eid
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Biot Number ◽  
Transfer Rate ◽  
Volume Fraction ◽  
Nanofluid Flow ◽  
Au Nps ◽  
Non Linear ◽  
Flow Similarity ◽  
The One

AbstractThe present mathematical simulation deals with the study of heat transfer characteristics of the shape of gold nanoparticles (Au-NPs) on blood flow past an exponentially stretching sheet using Sisko nanofluid taking into account the Biot number effect. Influences of non-linear thermal radiation and suction/injection are considered. The one-phase model is used to describe the Sisko nanofluid flow. Similarity variables are performed to convert the non-linear PDEs into ordinary ones. These equations together with initial and boundary conditions are provided in a non-dimensional form and then resolved numerically utilizing the fourth–fifth-order Runge–Kutta–Fehlberg (RKF45) technique. The attitude of diverse flow quantities is investigated and examined via the study of parameters like the Au-NP volume fraction, the non-linear stretching parameter, and the Biot number. It is found that the Biot number improves the heat transfer rate markedly. In the blowing case, the blade-shaped Au-NPs show the highest heat transfer rate; in the suction case, the contrary is observed for spherical Au-NPs.

scholarly journals Assisted convective heat transfer and entropy generation in a solar collector filled with nanofluid

2016 ◽  
Vol 13 (2) ◽  
pp. 135-150
Author(s):  
R. Nasrin ◽  
M.A. Alim ◽  
M. Hasanuzzzaman
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Entropy Generation ◽  
Solar Collector ◽  
Transfer Rate ◽  
Volume Fraction ◽  
Bulk Temperature ◽  
Outlet Temperature ◽  
Nanoparticle Volume Fraction ◽  
Collector Efficiency

Heat transfer phenomena of flat plate solar collector filled with different nanofluids has been investigated numerically. Galerkin’s Finite Element Method is used to solve the problem. Heat transfer rate, average bulk temperature, average sub-domain velocity, outlet temperature, thermal efficiency, mean entropy generation and Bejan number has been investigated by varying the solid nanoparticle volume fraction of water/Cu, water/Ag and water/Cu/Ag nanofluids from 0% to 3%. It is found that the solid nanoparticle volume fraction has great effect on heat transfer phenomena. It is observed that the increases of the solid volume fraction (up to 2%) enhances the heat transfer rate and collector efficiency where after 2% the rate of change almost constant. Higher heat transfer rate and collector efficiency has been obtained 19% and 13% for water/Ag nanofluid respectively.

scholarly journals Numerical Study of Natural Convection Heat Transfer in a Porous Annulus Filled with a Cu-Nanofluid

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 990
Author(s):  
Lingyun Zhang ◽  
Yupeng Hu ◽  
Minghai Li
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Volume Fraction ◽  
Convection Heat Transfer ◽  
Darcy Number ◽  
Radius Ratio ◽  
Natural Convection Heat Transfer ◽  
Nanoparticle Volume Fraction ◽  
Convection Heat

Natural convection heat transfer in a porous annulus filled with a Cu nanofluid has been investigated numerically. The Darcy–Brinkman and the energy transport equations are employed to describe the nanofluid motion and the heat transfer in the porous medium. Numerical results including the isotherms, streamlines, and heat transfer rate are obtained under the following parameters: Brownian motion, Rayleigh number (103–105), Darcy number (10−4–10−2), nanoparticle volume fraction (0.01–0.09), nanoparticle diameter (10–90 nm), porosity (0.1–0.9), and radius ratio (1.1–10). Results show that Brownian motion should be considered. The nanoparticle volume fraction has a positive effect on the heat transfer rate, especially with high Rayleigh number and Darcy number, while the nanoparticle diameter has an inverse influence. The heat transfer rate is enhanced with the increase of porosity. The radius ratio has a significant influence on the isotherms, streamlines, and heat transfer rate, and the rate is greatly enhanced with the increase of radius ratio.

MHD hybrid nanofluid flow with convective heat transfer over a permeable stretching/shrinking surface with radiation

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nur Syahirah Wahid ◽  
Norihan Md Arifin ◽  
Najiyah Safwa Khashi'ie ◽  
Ioan Pop ◽  
Norfifah Bachok ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Volume Fraction ◽  
Hybrid Nanofluid ◽  
Convective Boundary Conditions ◽  
Nanofluid Flow ◽  
Convective Boundary ◽  
Content Type ◽  
Shrinking Surface

Purpose The purpose of this paper is to numerically investigate the hybrid nanofluid flow with the imposition of magnetohydrodynamic (MHD) and radiation effects alongside the convective boundary conditions over a permeable stretching/shrinking surface. Design/methodology/approach The mathematical model is formulated in the form of partial differential equations (PDEs) and are then transformed into the form of ordinary differential equations (ODEs) by using the similarity variables. The deriving ODEs are solved numerically by using the bvp4c solver in MATLAB software. Stability analysis also has been performed to determine the stable solution among the dual solutions obtain. For method validation purposes, a comparison of numerical results has been made with the previous studies. Findings The flow and the heat transfer of the fluid at the boundary layer are described through the plot of the velocity profile, temperature profile, skin friction coefficient and local Nusselt number that are presented graphically. Dual solutions are obtained, but only the first solution is stable. For the realizable solution at the shrinking surface, the proliferation of nanoparticle volume fraction (copper) and magnetic (magnetohydrodynamics) parameters can impede the boundary layer separation. Also, Biot number could enhance the temperature profile and the heat transfer rate at the shrinking surface region. The incrementation of 0.1% of Biot number has enhanced the heat transfer rate by approximately 0.1% and the incrementation of 0.5% volume fraction for copper has reduced the heat transfer rate by approximately 0.17%. Originality/value The presented model and numerical results are original and new. It can be used as a future reference for further investigation and related practical application. The main contribution of this investigation includes giving the initial prediction and providing the numerical data for the other researchers for their future reference regarding the impacts of nanoparticles volumetric concentration towards the main physical quantities of interest in the presence of magnetic and radiation parameters with the convective boundary conditions.

scholarly journals Double Solutions and Stability Analysis of Micropolar Hybrid Nanofluid with Thermal Radiation Impact on Unsteady Stagnation Point Flow

Mathematics ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 276
Author(s):  
Nur Syazana Anuar ◽  
Norfifah Bachok
Keyword(s):  
Heat Transfer ◽  
Stability Analysis ◽  
Thermal Radiation ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Volume Fraction ◽  
Stable Solution ◽  
Shrinking Sheet ◽  
Hybrid Nanofluid ◽  
Micropolar Nanofluid

The mathematical modeling of unsteady flow of micropolar Cu–Al2O3/water nanofluid driven by a deformable sheet in stagnation region with thermal radiation effect has been explored numerically. To achieve the system of nonlinear ordinary differential equations (ODEs), we have employed some appropriate transformations and solved it numerically using MATLAB software (built-in solver called bvp4c). Influences of relevant parameters on fluid flow and heat transfer characteristic are discussed and presented in graphs. The findings expose that double solutions appear in shrinking sheet case in which eventually contributes to the analysis of stability. The stability analysis therefore confirms that merely the first solution is a stable solution. Addition of nanometer-sized particle (Cu) has been found to significantly strengthen the heat transfer rate of micropolar nanofluid. When the copper nanoparticle volume fraction increased from 0 to 0.01 (1%) in micropolar nanofluid, the heat transfer rate increased roughly to an average of 17.725%. The result also revealed that an upsurge in the unsteady and radiation parameters have been noticed to enhance the local Nusselt number of micropolar hybrid nanofluid. Meanwhile, the occurrence of material parameter conclusively decreases it.

scholarly journals A Weibull Distribution: Flow and Heat Transfer of Nanofluids Containing Carbon Nanotubes with Radiation and Velocity Slip Effects

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Izamarlina Asshaari ◽  
Alias Jedi ◽  
Kafi Dano Pati
Keyword(s):  
Heat Transfer ◽  
Carbon Nanotubes ◽  
Thermal Radiation ◽  
Weibull Distribution ◽  
Skin Friction ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Volume Fraction ◽  
Moving Plate ◽  
Flow And Heat Transfer

In this study, the Tiwari and Das model is numerically studied, in case of a moving plate containing both single-walled and multiwalled carbon nanotubes (SWCNTs and MWCNTs, respectively), in the presence of thermal radiation and the slip effect. Employing the similarity transformation, a set of 2nd-order partial differential equations (which are used to model the flow and heat transfer) are solved numerically using the boundary value problem with 4th-order accuracy (BVP4C) method. The effects of related parameters, such as the volume fraction of nanoparticles, moving, slip, and radiation parameter on the heat transfer performance are analysed and discussed. Results indicate that a unique solution was placed when the plate travels in assisting flow conditions. Additionally, as the nanoparticle volume fraction (φ) rises at φ = 0.2, the skin friction and heat transfer rate decrease. It is also observed that when the slip parameter (β) increases at β = 0.4, the skin friction decreases, whereas the heat transfer rate increases. Meanwhile, the heat transfer rate decreases when the thermal radiation (NR) increases to 0.7. Moreover, it is found that the SWCNTs are more efficient when the skin friction coefficient and the Nusselt number are considered. It is found that the Weibull distribution is more suitable in fitting the skin friction data.

scholarly journals Rotating Flow in a Nanofluid with CNT Nanoparticles over a Stretching/Shrinking Surface

Mathematics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Nor Azizah Yacob ◽  
Nor Fadhilah Dzulkifli ◽  
Siti Nur Alwani Salleh ◽  
Anuar Ishak ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Carbon Nanotubes ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Volume Fraction ◽  
Rotating Flow ◽  
Nanoparticle Volume Fraction ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Shrinking Surface

The steady three-dimensional rotating flow past a stretching/shrinking surface in water and kerosene-based nanofluids containing single and multi-walled carbon nanotubes (CNTs) is investigated. The governing equations are converted to similarity equations, and then numerically solved using MATLAB software. The impacts of rotational, suction, and nanoparticle volume fraction on the flow and the thermal fields, as well as velocity and temperature gradients at the surface, are represented graphically and are analyzed. Further, the friction factor and the heat transfer rate for different parameters are presented in tables. It is found that the heat transfer rate increases with increasing nanoparticle volume fraction as well as suction parameter in water and kerosene-based nanofluids of single and multi-walled CNTs. However, the increment in the rotating flow parameter decreases the rate of heat transfer. Multi-walled carbon nanotubes and kerosene-based nanofluid contribute to heat transfer rates better than single-walled carbon nanotubes and water-based nanofluid, respectively. A unique solution exists for the stretching surface, while two solutions are obtained for the shrinking surface. Further analysis of their stabilities shows that only one of them is stable over time.

Magnetohydrodynamic and Heat Transfer Impacts on Ferrofluid Over a Rotating Disk: An Application to Hard Disk Drives

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
V. Loganayagi ◽  
Peri K. Kameswaran
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Volume Fraction ◽  
Hall Current ◽  
Hard Disk Drives ◽  
Rotating Disk ◽  
Disk Drives ◽  
Nanoparticle Volume Fraction ◽  
Motor Oil

Abstract The motivation behind this article is to explore the impacts of heat transfer, magnetohydrodynamic, and hall current on two-dimensional incompressible nanofluid flow over a rotating disk. The nanofluid model utilized in the present investigation comprises the nanoparticle fraction model. Two sorts of nanoparticles to be specific Hematite (Fe2O3) is the principal source of iron and Cobalt alloy (Co64 Cr30 W6) is generally used metal alloy that is primarily Cobalt and Chromium with base fluid Motor Oil 10W30 is taken into consideration. The Prandtl number identifying with motor oil is (Pr = 1531.92). The governing equations are reduced to a system of ordinary differential equations by using Von-Karman transformation and then solved numerically utilizing matlab bvp4c. Impacts of the magnetic field, hall current, and nanoparticle volume fraction on tangential, radial velocities, and temperature profiles have been examined. Numerical outcomes have been acquired for various physical parameters through graphical representation. We have demonstrated that a remarkable reconciliation exists among the current outcomes and those in the literature for various values of magnetic parameter and velocity slip parameters, in the absence of other parameters. It is also found that radial and tangential velocities increase more in the case of Fe2O3 nanoparticles when compared with Co64 Cr30 W6 because of density variations. It is discovered that enhancement in a nanoparticle volume fraction reduces the heat transfer rate. It can moreover be clarified such a way that as the nanoparticle volume fraction raise, the density of nanoparticles increases, temperature also increases subsequently heat transfer rate decreases. This result keeps more cooling for the hard disk drives and might be intrigued for engineers.

scholarly journals Numerical heat transfer studies of a latent heat storage system containing nano-enhanced phase change material

2011 ◽  
Vol 15 (1) ◽  
pp. 169-181 ◽  
Author(s):  
A.A. Ranjbar ◽  
S. Kashani ◽  
S.F. Hosseinizadeh ◽  
M. Ghanbarpour
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Phase Change ◽  
Heat Transfer Rate ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Transfer Rate ◽  
Volume Fraction ◽  
Storage System ◽  
Nanoparticle Volume Fraction

The heat transfer enhancement in the latent heat thermal energy storage system through dispersion of nanoparticle is reported. The resulting nanoparticle-enhanced phase change materials (NEPCM) exhibit enhanced thermal conductivity in comparison to the base material. The effects of nanoparticle volume fraction and some other parameters such as natural convection are studied in terms of solid fraction and the shape of the solid-liquid phase front. It has been found that higher nanoparticle volume fraction result in a larger solid fraction. The present results illustrate that the suspended nanoparticles substantially increase the heat transfer rate and also the nanofluid heat transfer rate increases with an increase in the nanoparticles volume fraction. The increase of the heat release rate of the NEPCM shows its great potential for diverse thermal energy storage application.

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