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

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2300
Author(s):  
Salah Almurtaji ◽  
Naser Ali ◽  
Joao A. Teixeira ◽  
Abdulmajid Addali

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.

2021 ◽  
Vol 2119 (1) ◽  
pp. 012117
Author(s):  
V Ya Rudyak ◽  
G R Dashapilov ◽  
A A Shupik

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.


2020 ◽  
Vol 31 (23) ◽  
pp. 235402 ◽  
Author(s):  
Balaji Bakthavatchalam ◽  
Khairul Habib ◽  
R Saidur ◽  
Syed Shahabuddin ◽  
Bidyut Baran Saha

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Amin Asadi ◽  
Ibrahim M. Alarifi

Abstract It is known that ultrasonication has a certain effect on thermophysical properties and heat transfer of nanofluids. The present study is the continuation of the authors’ previous research on the effects of ultrasonication on the thermophysical properties of Multi-Walled Carbon Nanotubes (MWCNTs)-water nanofluid. Investigating the effects of ultrasonication time on samples’ stability, rheological properties, and pumping power of a water-based nanofluid containing MWCNTs nanoparticle is the main objective of the present study. The two-step method has been employed to prepared the samples. Moreover, a probe-type ultrasonic device has been used, and different ultrasonication times have been applied. The samples’ stability is investigated in different periods. The results revealed that prolonging the ultrasonication time to 60 min leads to improving the samples’ stability while prolonging ultrasonication time to higher than 60 min resulted in deteriorating the stability. As for dynamic viscosity, it is observed that increasing ultrasonication time to 60 min leads to decreasing the dynamic viscosity of the samples. As for pumping power, it is observed that the maximum increase in fanning friction factor ratio is less than 3%, which shows that adding MWCNTs to water does not impose a considerable penalty in the required energy for pumping power.


2021 ◽  
Vol 66 (4) ◽  
pp. 1717-1729 ◽  
Author(s):  
Carlos Alberto Nieto de Castro ◽  
Ana Paula da Costa Ribeiro ◽  
Andreia Oliveira Figueiras ◽  
Elisa Langa ◽  
Salomé Inês Cardoso Vieira ◽  
...  

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