Heat transfer in water-based nanofluids

فاقد چكيده

Nanofluids are considered to offer important advantages over conventional heat transfer fluids.Usual heat transfer fluids with suspended ultrafine particles of nanometer size are named as nanofluids, which have opened a new dimension in heat transfer processes. some of metallic or nonmetallic nanopowders in base liquid effect in heat conduction of nanofluid.over a decade ago, researchers focused on measuring and modeling the effective thermal conductivity and viscosity of nanofluids.Recently important theoretical and experimental research works on convective heat transfer appeared in the open literatures on the enhancement of heat transfer using suspensions of nano-meter-sized solid particle materials, metallic or nonmetallic in base heat transfer fluids .This paper presents the increase of thermal conductivity with temperatures for nanofluids with water as base fluid and particles of Al2O3, Zirconium or CuO as suspension material. Transient hot-wire method is used for the measurement of thermal conductivity. Heat retaining time is introduced and estimated experimentally. The results indicate an enhancement of thermal conductivity with temperature found to be agreeing excellently with a wide range of different models as well as the data published in literature.