Experimental and numerical investigation of heat transfer in CNT nanofluids

Nanofluids with their enhanced thermal conductivity are believed to be a promising coolant in heat transfer applications. In this study, carbon nanotube (CNT) nanofluids of 0.01 wt%, stabilised by 1.0 wt% gum arabic were used as a cooling liquid in a concentric tube laminar flow heat exchanger. The...

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Bibliographic Details
Main Authors: Rashmi, Walvekar, Siddiqui, Mohammad Khalid, Ismail, Ahmad Faris, Saidur, R., Rashid, A. K.
Format: Article
Language:English
Published: Taylor & Francis 2015
Subjects:
Online Access:http://irep.iium.edu.my/42765/
http://irep.iium.edu.my/42765/
http://irep.iium.edu.my/42765/
http://irep.iium.edu.my/42765/1/Experimental_Nanoscience2015a.pdf
Description
Summary:Nanofluids with their enhanced thermal conductivity are believed to be a promising coolant in heat transfer applications. In this study, carbon nanotube (CNT) nanofluids of 0.01 wt%, stabilised by 1.0 wt% gum arabic were used as a cooling liquid in a concentric tube laminar flow heat exchanger. The flow rate of cold fluid varied from 10 to 50 g/s. Both experimental and numerical simulations were carried out to determine the heat transfer enhancement using CNT nanofluids. Computational fluid dynamics (CFD) simulations were carried out using Fluent v 6.3 by assuming single-phase approximation. Thermal conductivity, density and rheology of the nanofluid were also measured as a function of temperature. The results showed thermal conductivity enhancement from 4% to 125% and nearly 70% enhancement in heat transfer with increase in flow rate. Numerical results exhibited good agreement with the experimental results with a deviation of +-3:0%. CNT nanofluids at 0.01 wt% CNTs showed Newtonian behaviour with no significant increase in the density.