Convective Heat Transfer Characteristics of Low Concentration CuO-Water Nanofluids in the Turbulent Flow Regime Based on an Artificial Intelligence Models

Author(s):  
Mehdi Mehrabi ◽  
Mohsen Sharifpur ◽  
Josua P. Meyer
Author(s):  
Daniel J. Faulkner ◽  
David R. Rector ◽  
Justin J. Davidson ◽  
Reza Shekarriz

Much attention has been paid in recent years to the use of nanoparticle suspensions for enhanced heat transfer. The majority of this work has focused on the thermal conductivity of these nanofluids, which can be as much as 2.5 times higher than that of the plain base fluid. The present work moves beyond measurements of non-flowing liquids, to explore the role that nanofluids can play in enhancing convective heat transfer within microscale channels. A unique pseudo-turbulent flow regime is postulated, which simulates turbulent behavior at very low Reynolds numbers, in what are nominally laminar flows. The resulting fluid mixing has the potential to raise the average convective heat transfer coefficient within the channel. Numerical modeling, using the lattice Boltzmann method, confirms the existence of the pseudo-turbulent flow regime. Finally, experimental results are presented which demonstrate a significant heat transfer enhancement when using nanofluids in forced convection. The current results are especially relevant to microchannel heatsinks, where the low Reynolds numbers impose limitations on the maximum Nusselt number achievable.


Author(s):  
Kyo Sik Hwang ◽  
Hyo Jun Ha ◽  
Seung Hyun Lee ◽  
Hyun Jin Kim ◽  
Seok Pil Jang ◽  
...  

This paper is to investigate flow and convective heat transfer characteristics of nanofluids with various shapes of Al2O3 nanoparticles flowing through a uniformly heated circular tube under fully developed laminar flow regime. For the purpose, Al2O3 nanofluids of 0.3 Vol.% with sphere, rod, platelet, blade and brick shapes are manufactured by a two-step method. Zeta potential as well as TEM image is experimentally obtained to examine suspension and dispersion characteristics of Al2O3 nanofluids with various shapes. To investigate flow characteristics, the pressure drop of Al2O3 nanofluids with various shapes are measured. In order to investigate convective heat transfer characteristics, the effective thermal conductivities of Al2O3 nanofluids with various shapes, the temperature distribution at the tube surface and the mean temperature of nanofluids at the inlet are measured, respectively. Based on the experimental results, the convective heat transfer coefficient of Al2O3 nanofluids with various shapes is compared with that of pure water and the thermal conductivity of Al2O3 nanofluids with various shapes. Thus, the effect of nanoparticles shape on the flow and convective heat transfer characteristics flowing through a uniformly heated circular tube under fully developed laminar flow regime is experimentally investigated.


Sign in / Sign up

Export Citation Format

Share Document