Heat transfer and entropy generation characteristics of nanofluid flow over bluff bodies under steady and unsteady flow: A two-phase approach

Owing to higher thermal conductivity, nanofluids have the potential to be the coolant for various applications ranging from internal to external flows. A two-phase model is implemented to model the interaction between nanoparticles and base fluid to obtain accurate results. Heat transfer and entropy...

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Main Authors: Advait V. Krishna, Anwesha Varma, Kottayat Nidhul
Format: Article
Language:English
Published: Elsevier 2024-11-01
Series:Case Studies in Thermal Engineering
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Online Access:http://www.sciencedirect.com/science/article/pii/S2214157X24012735
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author Advait V. Krishna
Anwesha Varma
Kottayat Nidhul
author_facet Advait V. Krishna
Anwesha Varma
Kottayat Nidhul
author_sort Advait V. Krishna
collection DOAJ
description Owing to higher thermal conductivity, nanofluids have the potential to be the coolant for various applications ranging from internal to external flows. A two-phase model is implemented to model the interaction between nanoparticles and base fluid to obtain accurate results. Heat transfer and entropy generation characteristics of nanofluid (Al2O3 and water) flow over bluff bodies such as circular and square cylinders for steady (20 < Re < 100) and unsteady (Re = 150 and 300) flow conditions have been carried out for various volume fractions (0.5–2 %). The same has been expressed in quantitative and qualitative aspects with parameters such as mean Nusselt number, surface Nusselt number, heat transfer enhancement ratio, and entropy generation. Heat transfer rate increases with an increase in flow rate and volume fraction for both steady and unsteady flow. Heat transfer enhancement in steady flow ranges from 1.10 to 1.35. For unsteady flow (Re = 150 &amp; Re = 300), nanofluid's heat transfer enhancement ratio is higher than water in the range of 1.10–1.8. This is attributed to the early separation of flow and the presence of large recirculatory regions. With the increase in Re, the entropy generation decreases for circular and square cylinders. Compared to nanofluid, the entropy generation is higher for water.
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spelling doaj-art-9a095d03b0e94da9868f7a1b017a21662024-11-14T04:31:43ZengElsevierCase Studies in Thermal Engineering2214-157X2024-11-0163105242Heat transfer and entropy generation characteristics of nanofluid flow over bluff bodies under steady and unsteady flow: A two-phase approachAdvait V. Krishna0Anwesha Varma1Kottayat Nidhul2Renewable Energy Center, Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, IndiaRenewable Energy Center, Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, IndiaCorresponding author.; Renewable Energy Center, Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, IndiaOwing to higher thermal conductivity, nanofluids have the potential to be the coolant for various applications ranging from internal to external flows. A two-phase model is implemented to model the interaction between nanoparticles and base fluid to obtain accurate results. Heat transfer and entropy generation characteristics of nanofluid (Al2O3 and water) flow over bluff bodies such as circular and square cylinders for steady (20 < Re < 100) and unsteady (Re = 150 and 300) flow conditions have been carried out for various volume fractions (0.5–2 %). The same has been expressed in quantitative and qualitative aspects with parameters such as mean Nusselt number, surface Nusselt number, heat transfer enhancement ratio, and entropy generation. Heat transfer rate increases with an increase in flow rate and volume fraction for both steady and unsteady flow. Heat transfer enhancement in steady flow ranges from 1.10 to 1.35. For unsteady flow (Re = 150 &amp; Re = 300), nanofluid's heat transfer enhancement ratio is higher than water in the range of 1.10–1.8. This is attributed to the early separation of flow and the presence of large recirculatory regions. With the increase in Re, the entropy generation decreases for circular and square cylinders. Compared to nanofluid, the entropy generation is higher for water.http://www.sciencedirect.com/science/article/pii/S2214157X24012735NanofluidMixture modelHeat transfer enhancementUnsteady flowEntropy generation
spellingShingle Advait V. Krishna
Anwesha Varma
Kottayat Nidhul
Heat transfer and entropy generation characteristics of nanofluid flow over bluff bodies under steady and unsteady flow: A two-phase approach
Case Studies in Thermal Engineering
Nanofluid
Mixture model
Heat transfer enhancement
Unsteady flow
Entropy generation
title Heat transfer and entropy generation characteristics of nanofluid flow over bluff bodies under steady and unsteady flow: A two-phase approach
title_full Heat transfer and entropy generation characteristics of nanofluid flow over bluff bodies under steady and unsteady flow: A two-phase approach
title_fullStr Heat transfer and entropy generation characteristics of nanofluid flow over bluff bodies under steady and unsteady flow: A two-phase approach
title_full_unstemmed Heat transfer and entropy generation characteristics of nanofluid flow over bluff bodies under steady and unsteady flow: A two-phase approach
title_short Heat transfer and entropy generation characteristics of nanofluid flow over bluff bodies under steady and unsteady flow: A two-phase approach
title_sort heat transfer and entropy generation characteristics of nanofluid flow over bluff bodies under steady and unsteady flow a two phase approach
topic Nanofluid
Mixture model
Heat transfer enhancement
Unsteady flow
Entropy generation
url http://www.sciencedirect.com/science/article/pii/S2214157X24012735
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AT anweshavarma heattransferandentropygenerationcharacteristicsofnanofluidflowoverbluffbodiesundersteadyandunsteadyflowatwophaseapproach
AT kottayatnidhul heattransferandentropygenerationcharacteristicsofnanofluidflowoverbluffbodiesundersteadyandunsteadyflowatwophaseapproach