scholarly journals Surface modification of carbon nanotubes with copper oxide nanoparticles for heat transfer enhancement of nanofluids

RSC Advances ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 1791-1802 ◽  
Author(s):  
Abdallah D. Manasrah ◽  
Ismail W. Almanassra ◽  
Nedal N. Marei ◽  
Usamah A. Al-Mubaiyedh ◽  
Tahar Laoui ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Surface Modification ◽  
Copper Oxide ◽  
Heat Transfer Enhancement ◽  
Copper Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Transfer Enhancement ◽  
Thermal Enhancement

Over the last few years, nanoparticles have been used as thermal enhancement agents in many heat transfer based fluids to improve the thermal conductivity of the fluids.

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.

PDMS nanocomposites for heat transfer enhancement in microfluidic platforms

Lab on a Chip ◽  
2014 ◽  
Vol 14 (17) ◽  
pp. 3419-3426 ◽  
Author(s):  
Pyshar Yi ◽  
Robiatun A. Awang ◽  
Wayne S. T. Rowe ◽  
Kourosh Kalantar-zadeh ◽  
Khashayar Khoshmanesh
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Transfer Enhancement ◽  
Transfer Enhancement ◽  
Microfluidic Platforms

This work introduces a method to enhance the thermal conductivity of PDMS microfluidic platforms through the use of PDMS/Al2O3 nanocomposites.

Enhanced thermal conductivity by aggregation in heat transfer nanofluids containing metal oxide nanoparticles and carbon nanotubes

2008 ◽  
Vol 92 (2) ◽  
pp. 023110 ◽  
Author(s):  
Jesse Wensel ◽  
Brian Wright ◽  
Dustin Thomas ◽  
Wayne Douglas ◽  
Bert Mannhalter ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Metal Oxide ◽  
Metal Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Enhanced Thermal Conductivity

Validity of performance factors used in recent studies on heat transfer enhancement by surface modification or insert devices

2022 ◽  
Vol 186 ◽  
pp. 122431
Author(s):  
Siti Nurul Akmal Yusof ◽  
Nura Mu'az Muhammad ◽  
Wan Mohd Arif Aziz Japar ◽  
Yutaka Asako ◽  
Chungpyo Hong ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Surface Modification ◽  
Heat Transfer Enhancement ◽  
Transfer Enhancement ◽  
Performance Factors

Calculation of Thermal Conductivity in Nanofluids From Atomic-Scale Simulations

2005 ◽  
Author(s):  
Xuan Wu ◽  
Ranganathan Kumar ◽  
Parveen Sachdeva
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Transfer Enhancement ◽  
Pure Water ◽  
Research Work ◽  
Atomic Scale ◽  
Heat Current ◽  
Transfer Enhancement ◽  
Atomic Interactions ◽  
Time Autocorrelation Function

Nanofluids that consist of nanometer sized particles and fibers dispersed in base liquids have shown the potential to enhance the heat transfer performance. Although three features of nanofluids including anomalously high thermal conductivities at very low nanoparticle concentrations, strongly temperature dependent thermal conductivity and significant increases in critical heat flux have been studied widely, and layering of liquid molecules at the particle-liquid interface, ballistic nature of heat transport in nanoparticles, and nanoparticle clustering are considered as the possible causations responsible for such kind of heat transfer enhancement, few research work from atomic-scale has been done to verify or explain those fascinating features of nanofluids. In this paper, a molecular dynamic model, which incorporates the atomic interactions for silica by BKS potential with a SPC/E model for water, has been established. To ensure the authenticity of our model, the position of each atom in the nanoparticle is derived by the crystallographic method. The interfacial interactions between the nanoparticle and water are simplified as the sum of interaction between many ions. Due to the electrostatic interaction, the ions on the nanoparticle’s surface can attract a certain number of water molecules, therefore, the effect of interaction between the nanoparticle and water on heat transfer enhancement in nanofluids is studied. By using Green-Kubo equations which set a bridge between thermal conductivity and time autocorrelation function of the heat current, a model which may derive thermal conductivity of dilute nanofluids that consist of silica nanoparticles and pure water is built. Several simulation results have been provided which can reveal the possible mechanism of heat enhancement in nanofluids.

scholarly journals Investigation of the novelty of latent functionally thermal fluids as alternative to nanofluids in natural convective flows

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zoubida Haddad ◽  
Farida Iachachene ◽  
Eiyad Abu-Nada ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Transfer Enhancement ◽  
Volume Fraction ◽  
Heat Of Fusion ◽  
Transfer Enhancement ◽  
Maximum Heat ◽  
Thermal Fluids ◽  
Maximum Heat Transfer ◽  
Wide Range

AbstractThis paper presents a detailed comparison between the latent functionally thermal fluids (LFTFs) and nanofluids in terms of heat transfer enhancement. The problem used to carry the comparison is natural convection in a differentially heated cavity where LFTFs and nanofluids are considered the working fluids. The nanofluid mixture consists of Al2O3 nanoparticles and water, whereas the LFTF mixture consists of a suspension of nanoencapsulated phase change material (NEPCMs) in water. The thermophysical properties of the LFTFs are derived from available experimental data in literature. The NEPCMs consist of n-nonadecane as PCM and poly(styrene-co-methacrylic acid) as shell material for the encapsulation. Finite volume method is used to solve the governing equations of the LFTFs and the nanofluid. The computations covered a wide range of Rayleigh number, 104 ≤ Ra ≤ 107, and nanoparticle volume fraction ranging between 0 and 1.69%. It was found that the LFTFs give substantial heat transfer enhancement compared to nanofluids, where the maximum heat transfer enhancement of 13% was observed over nanofluids. Though the thermal conductivity of LFTFs was 15 times smaller than that of the base fluid, a significant enhancement in thermal conductivity was observed. This enhancement was attributed to the high latent heat of fusion of the LFTFs which increased the energy transport within the cavity and accordingly the thermal conductivity of the LFTFs.

Copper Oxide Nanoparticles Are Highly Toxic: A Comparison between Metal Oxide Nanoparticles and Carbon Nanotubes

2008 ◽  
Vol 21 (9) ◽  
pp. 1726-1732 ◽  
Author(s):  
Hanna L. Karlsson ◽  
Pontus Cronholm ◽  
Johanna Gustafsson ◽  
Lennart Möller
Keyword(s):  
Carbon Nanotubes ◽  
Metal Oxide ◽  
Copper Oxide ◽  
Metal Oxide Nanoparticles ◽  
Copper Oxide Nanoparticles ◽  
Oxide Nanoparticles
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