Thermophysical properties, heat transfer and pressure drop of COOH-functionalized multi walled carbon nanotubes/water nanofluids

To evaluate the synthesis and characterization of MWCNT (Multi-walled Carbon Nanotubes) with different degrees of functionalization in distilled water. The thermophysical properties (thermal conductivity and viscosity) of these nanofluids were measured at a temperature range (20-60°C) and concentrations (0.005-0.05%) by volume. Increases in thermal conductivity and viscosity were found 9.3% and 4.7%, respectively, at a volumetric concentration of 0.01% at a temperature of 30°C. The study of new fluids that improve the rate of removal of heat is fundamental to obtain greater efficiency of energy systems. Among the several factors that compromise the efficiency of the energy systems, we can highlight the thermophysical limitations of the conventional fluids, inhibiting in a very significant way some industrial applications. In this work we intend to improve the heat transfer characteristics of fluids commonly used by the addition of nanoparticles, made up of carbon nanotubes, in water which is the most used fluid for the cooling of nuclear reactors in operation today. It is intended to improve the heat transfer characteristics of fluids commonly used by the addition of nanoparticles, made of carbon nanotubes, through the addition of nanoparticles, made up of carbon nanotubes, in water which is the most used fluid for refrigeration of nuclear reactors currently in operation. In order to assess its benefits for the applicability and nuclear systems, ie primary coolant, safety systems, major accident mitigation strategies.

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Comparison between multi-walled carbon nanotubes and titanium dioxide nanoparticles as additives on performance of turbine meter oil nano lubricant

Scientific Reports ◽

10.1038/s41598-021-90625-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hadi Pourpasha ◽

Saeed Zeinali Heris ◽

Yaghob Mohammadfam

Keyword(s):

Carbon Nanotubes ◽

Titanium Dioxide ◽

Friction Coefficient ◽

Pressure Drop ◽

Mass Fraction ◽

Viscosity Index ◽

Wear Depth ◽

Nano Lubricant ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

AbstractThis research aims of compare the impact of the mass fraction of multi-walled carbon nanotubes (MWCNTs) and titanium dioxide (TiO2) nano additive on the tribological and thermophysical attributes of turbine meter oil. These attributes include the average friction coefficient, pressure drop, wear, flash point, pour point, relative viscosity, kinematics viscosity, and viscosity index. The pressure drops and the average friction coefficient inside the copper tube were simulated and compared with experimental results. In this study, for the synthesis of nano lubricants from turbine meter oil as a pure fluid and from MWCNTs and TiO2 as nano additives in the mass fraction of 0.05, 0.1, 0.2, 0.3, and 0.4 wt.% and from oleic acid and Triton x100 as surfactants were utilized. The results illustrated that the wear depth of copper pins in the presence of nano lubricant with 0.4 wt.% of MWCNTs and 0.1 wt.% TiO2 was improved by 88.26% and 71.43%, respectively. Increasing 0.3 wt.% of TiO2 and MWCNTs into the oil caused to improvement in viscosity index. The simulation data and experimental data for the pressure drop were closer together and indicated a minor error that the maximum error is less than 10%.

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Fe3O4 nanoparticles decorated multi-walled carbon nanotubes based magnetic nanofluid for heat transfer application

Materials Letters ◽

10.1016/j.matlet.2020.128043 ◽

2020 ◽

Vol 274 ◽

pp. 128043

Author(s):

Shahir Hussain ◽

Md. Mottahir Alam ◽

Mohd Imran ◽

Nasser Zouli ◽

Abdul Aziz ◽

...

Keyword(s):

Heat Transfer ◽

Carbon Nanotubes ◽

Fe3o4 Nanoparticles ◽

Magnetic Nanofluid ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

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Synthesis, stability, and thermophysical properties of aqueous colloidal dispersions of multi-walled carbon nanotubes treated with beta-alanine

International Communications in Heat and Mass Transfer ◽

10.1016/j.icheatmasstransfer.2017.09.006 ◽

2017 ◽

Vol 89 ◽

pp. 7-17 ◽

Cited By ~ 7

Author(s):

Wail Sami Sarsam ◽

Ahmad Amiri ◽

Mehdi Shanbedi ◽

S.N. Kazi ◽

A. Badarudin ◽

...

Keyword(s):

Carbon Nanotubes ◽

Thermophysical Properties ◽

Colloidal Dispersions ◽

Beta Alanine ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

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Effect of Multi-Walled Carbon Nanotubes-Based Nanofluids on Marine Gas Turbine Intercooler Performance

Nanomaterials ◽

10.3390/nano11092300 ◽

2021 ◽

Vol 11 (9) ◽

pp. 2300

Author(s):

Salah Almurtaji ◽

Naser Ali ◽

Joao A. Teixeira ◽

Abdulmajid Addali

Keyword(s):

Carbon Nanotubes ◽

Gas Turbine ◽

Thermophysical Properties ◽

Outlet Temperature ◽

Gas Temperature ◽

Pumping Power ◽

Turbine Engine ◽

Compressed Gas ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

Coolants play a major role in the performance of heat exchanging systems. In a marine gas turbine engine, an intercooler is used to reduce the compressed gas temperature between the compressor stages. The thermophysical properties of the coolant running within the intercooler directly influence the level of enhancement in the performance of the unit. Therefore, employing working fluids of exceptional thermal properties is beneficial for improving performance in such applications, compared to conventional fluids. This paper investigates the effect of utilizing nanofluids for enhancing the performance of a marine gas turbine intercooler. Multi-walled carbon nanotubes (MWCNTs)-water with nanofluids at 0.01–0.10 vol % concentration were produced using a two-step controlled-temperature approach ranging from 10 °C to 50 °C. Next, the thermophysical properties of the as-prepared suspensions, such as density, thermal conductivity, specific heat capacity, and viscosity, were characterized. The intercooler performance was then determined by employing the measured data of the MWCNTs-based nanofluids thermophysical properties in theoretical formulae. This includes determining the intercooler effectiveness, heat transfer rate, gas outlet temperature, coolant outlet temperature, and pumping power. Finally, a comparison between a copper-based nanofluid from the literature with the as-prepared MWCNTs-based nanofluid was performed to determine the influence of each of these suspensions on the intercooler performance.

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Measurement and study of thermophysical properties of nanofluids with carbon nanotubes

Journal of Physics Conference Series ◽

10.1088/1742-6596/2119/1/012117 ◽

2021 ◽

Vol 2119 (1) ◽

pp. 012117

Author(s):

V Ya Rudyak ◽

G R Dashapilov ◽

A A Shupik

Keyword(s):

Carbon Nanotubes ◽

Electrical Conductivity ◽

Light Scattering ◽

Dynamic Light Scattering ◽

Thermophysical Properties ◽

Weight Concentration ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes ◽

Single Walled Cnts ◽

Walled Cnts

Abstract This article is devoted to the study of the thermophysical properties of nanofluids with single-walled and multi-walled carbon nanotubes (CNT). Their weight concentration varied from 0.05 to 0.2%. Nanofluids, based on ethylene glycol and water, were studied. Dispersants were also used. The diffusion of CNT had been systematically investigated by the method of dynamic light scattering and their effective hydrodynamic dimensions were determined. The rheology and viscosity of all nanofluids were studied. It is shown that nanofluids are either pseu-doplastic or viscoplastic. Their rheology changes with increasing CNT concentration and temperature. However, in all cases, the viscosity of nanofluids with single-walled CNTs is signifi-cantly higher than that of nanofluids with multi-walled CNTs. In the last part, the electrical conductivity of all these nanofluids and the dispersants effect on it are investigated.

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Influence of solvents on the enhancement of thermophysical properties and stability of multi-walled carbon nanotubes nanofluid

Nanotechnology ◽

10.1088/1361-6528/ab79ab ◽

2020 ◽

Vol 31 (23) ◽

pp. 235402 ◽

Cited By ~ 5

Author(s):

Balaji Bakthavatchalam ◽

Khairul Habib ◽

R Saidur ◽

Syed Shahabuddin ◽

Bidyut Baran Saha

Keyword(s):

Carbon Nanotubes ◽

Thermophysical Properties ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes ◽

Influence Of Solvents

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Thermal Efficiency, Heat Transfer, and Friction Factor Analyses of MWCNT + Fe3O4/Water Hybrid Nanofluids in a Solar Flat Plate Collector under Thermosyphon Condition

Processes ◽

10.3390/pr9010180 ◽

2021 ◽

Vol 9 (1) ◽

pp. 180 ◽

Cited By ~ 1

Author(s):

Bahaa Saleh ◽

Lingala Syam Sundar

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Carbon Nanotubes ◽

Friction Factor ◽

Thermal Efficiency ◽

Volume Concentration ◽

Multi Walled Carbon Nanotubes ◽

Hybrid Nanofluids ◽

Flat Plate Collector ◽

Walled Carbon Nanotubes

The heat transfer, friction factor, and collector efficiency are estimated experimentally for multi-walled carbon nanotubes+Fe3O4 hybrid nanofluid flows in a solar flat plate collector under thermosyphon circulation. The combined technique of in-situ growth and chemical coprecipitation was utilized to synthesize the multi-walled carbon nanotubes+Fe3O4 hybrid nanoparticles. The experiments were carried out at volume flow rates from 0.1 to 0.75 L/min and various concentrations from 0.05% to 0.3%. The viscosity and thermal conductivity of the hybrid nanofluids were experimentally measured at different temperatures and concentrations. Due to the improved thermophysical properties of the hybrid nanofluids, the collector achieved better thermal efficiency. Results show that the maximum thermal conductivity and viscosity enhancements are 28.46% and 50.4% at 0.3% volume concentration and 60 °C compared to water data. The Nusselt number, heat transfer coefficient, and friction factor are augmented by 18.68%, 39.22%, and 18.91% at 0.3% volume concentration and 60 °C over water data at the maximum solar radiation. The collector thermal efficiency improved by 28.09% at 0.3 vol. % at 13:00 h daytime and a Reynolds number of 1413 over water data. Empirical correlations were developed for friction factor and Nusselt number.

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