Field-Synergy and Figure-of-Merit Analysis of Two Oxide–Water-Based Nanofluids' Flow in Heated Tubes

ABSTRACT

Field-synergy analysis is performed on the water–oxide nanofluid flow in circular heat sinks to examine the synergetic relation between the flow and temperature fields for heating processes. By varying the Reynolds number and the nanoparticle volume fraction, the convective heat transfer of nanofluid is investigated based on the field synergy number. For heating, the degree of synergy between the velocity and temperature fields of nanofluid flow deteriorates with the Reynolds number increase, leading to a decreased heat transfer performance of the nanofluid. By increasing the particle volume fraction, the degree of synergy between the velocity and temperature fields of the nanofluid flow can be intensified, thus going to convection heat transfer enhancement. After generating results, one can notice that the heat transfer enhancement is strongly dependent on nanoparticle type, Reynolds number, and volume fraction. The results are similar, even if the thermal conductivity of the two considered oxide nanoparticles are quite different. Additionally, a convenient figure of merit that is known as the Mouromtseff number was used as base of comparison, and the results indicated that the considered nanofluids can successfully replace water in specific applications for single-phase forced convection flow in a tube.

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Notes on contributors

Alina Adriana Minea

Alina Adriana Minea is full professor at Technical University “Gheorghe Asachi” from Iasi, Romania, and has published more than 120 articles (45 of which are in international peer-reviewed journals) and authored or co-authored 17 books, most of them in the field of heat transfer. She received her M.Sc. and Ph.D. degrees from the Technical University “Gheorghe Asachi” from Iasi. In 2013 she obtained the habilitation title. She has been teaching at the Technical University “Gheorghe Asachi” from Iasi since 1998 and her current research interests include heat transfer in industrial equipment, based on modifying heat chamber geometry and improving energy consumption, as well as nanofluids as a heat transfer enhancement technique. She is a member of the Management Committee for COST action “Overcoming Barriers to Nanofluids Market” and currently serves as a member of the regional editorial board of the journal Thermal Sciences and as a reviewer for many peer-reviewed journals and conferences.

Oronzio Manca

Oronzio Manca is a professor at Seconda Università degli Studi di Napoli (SUN). He was coordinator of the mechanical engineering courses from November 2000 to December 2004 and of the industrial engineering area from January 2005 to October 2011 at SUN. He earned his M.Sc. degree in mechanical engineering at Università degli Studi di Napoli, Napoli, Italy, in July 1979. His main scientific activities are on heat transfer and applied thermodynamics. He is a member of the American Society of Mechanical Engineering and Unione Italiana di Termofluidodinamica, UIT. He is an author or co-author of 345 scientific papers (90 in international peer-reviewed journals). He has been an associate editor for the ASME Journal of Heat Transfer from July 2010 to June 2013 and Journal of Porous Media from September 2010 and one of the editors of the new journal Nano Energy and Nano Environment from July 2011. He is currently a member of the editorial advisory boards for The Open Thermodynamics Journal, Advances in Mechanical Engineering, and The Open Fuels and Energy Science Journal.