title: Numerical investigation of heat transfer enhancement in a rectangular heated pipe for turbulent nanofluid.
abstract: Thermal characteristics of turbulent nanofluid flow in a rectangular pipe have been investigated numerically. The continuity, momentum, and energy equations were solved by means of a finite volume method (FVM). The symmetrical rectangular channel is heated at the top and bottom at a constant heat flux while the sides walls are insulated. Four different types of nanoparticles Al2O3, ZnO, CuO, and SiO2 at different volume fractions of nanofluids in the range of 1% to 5% are considered in the present investigation. In this paper, effect of different Reynolds numbers in the range of 5000 < Re < 25000 on heat transfer characteristics of nanofluids flowing through the channel is investigated. The numerical results indicate that SiO2-water has the highest Nusselt number compared to other nanofluids while it has the lowest heat transfer coefficient due to low thermal conductivity. The Nusselt number increases with the increase of the Reynolds number and the volume fraction of nanoparticles. The results of simulation show a good agreement with the existing experimental correlations.
authors.affiliation: Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Hooman
authors.identifier: 0000-0002-0904-198X
authors.initials: H
authors.lastname: Yarmand
authors.affiliation: Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Samira
authors.identifier: 0000-0001-8090-4349
authors.initials: S
authors.lastname: Gharehkhani
authors.affiliation: Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Salim Newaz
authors.initials: SN
authors.lastname: Kazi
authors.affiliation: Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Emad
authors.initials: E
authors.lastname: Sadeghinezhad
authors.affiliation: Young Researchers and Elite Club, Islamic Azad University, Mashhad Branch, Mashhad, Iran.
authors.forename: Mohammad Reza
authors.identifier: 0000-0001-7301-2561
authors.initials: MR
authors.lastname: Safaei
mesh_terms: D000465:Algorithms; D000537:Aluminum Oxide / Q000737:chemistry; D003198:Computer Simulation; D003300:Copper / Q000737:chemistry; D006358:Hot Temperature; D057446:Hydrodynamics; D008956:Models, Chemical; D053758:Nanoparticles / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D013814:Thermal Conductivity; D014867:Water / Q000737:chemistry*; D015034:Zinc Oxide / Q000737:chemistry
chemical_list: D014867:Water; D012822:Silicon Dioxide; D003300:Copper; D000537:Aluminum Oxide; D015034:Zinc Oxide; C030973:cupric oxide