Heat Transfer in Laminar Graetz and Taylor Flows Incorporating Nanoparticles

Abstract

This study investigates the thermal and hydrodynamic effects of incorporating nanomaterials to the continuous and gas-liquid Taylor flows in mini scale tubes. Aluminum Oxide nanopowder was dispersed in distilled water to produce three nanofluid concentrations: 1, 2 and 4 wt% using a two-step method. Heat transfer enhancement in miniscale tubes ($\sim$1.5 mm) was assessed using Nusselt number and dimensionless mean wall heat flux. The experiments were conducted under laminar developing flow with isothermal boundary condition. In addition, nanofluid experiments covered: thermal conductivity measurements, scanning electronic microscopy, and performance efficiency analysis. The thermal and hydrodynamic effects of incorporating nanoparticles to the base fluid were evaluated using performance efficiency analysis which considers friction factor and Nusselt number. The results demonstrated that heat transfer enhancement is associated with the nanoparticles concentration when compared with Graetz theory. Total enhancement in segmented nanofluid flows was observed to be a combination of the individual contributions of internal circulations within the liquid slugs and the interaction between the nanoparticles. Overall, the present study highlights the potential of heat transfer enhancement within mini/micro tubes using segmented nanofluid flows.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors acknowledge the financial support of the Natural Sciences and Engineering Research Council (NSERC 200439) of Canada for providing funding under the Discovery Research Grants program. The first author acknowledges the financial support of Ministry of High Education, Libya under the scholarship program.

Notes on contributors

Khalifa Alrbee

Khalifa Alrbee is a postdoctoral researcher at Memorial University of Newfoundland. He obtained his Ph.D. in mechanical engineering at Memorial University in 2020. In 2008, he completed his Master of Science at Libyan Academy. He conducted research on nanofluid's stability and preparation. He conducted research on heat transfer enhancement using gas-liquid and liquid-liquid Taylor flows in mini scale channels. He was involved in a research related to solar water heating using two-phase flow for his Ph.D. studies.

Yuri Muzychka

Yuri Muzychka joined the Faculty of Engineering and Applied Science at Memorial University of Newfoundland in 2000. He completed his Ph.D. in 1999 at the University of Waterloo. Since joining Memorial University, he has focused his research efforts in several areas of heat transfer and fluid dynamics, namely, convection and conduction heat transfer, thermal management in electronics packaging, internal fluid flow, two-phase flow, and marine icing phenomena. He has published approximately 110 papers in high quality journals and 100 conference papers at international conferences.

Xili Duan

Xili Duan is an Associate Professor in Mechanical Engineering at Memorial University of Newfoundland. He received his Ph.D. degree in mechanical engineering from the University of Manitoba. His research interests include interfacial fluid dynamics and heat transfer, with applications in energy conversion and storage, thermal management, flow drag reduction and multiphase separation, and engineering safety in harsh marine environments. He has published 3 book chapters and over 100 journal and conference papers.