ABSTRACT
In this study, the effect of the constant magnetic field (MF) on the convective heat transfer characteristics of Fe3O4/H2O ferro-nano-fluid with different nano-fluid volumetric concentrations (1.0%, 2.0%, and 5.0%) flowing in a circular pipe has been studied experimentally. Experiments have been conducted under laminar flow regime (1000≤ Re≤2300). Based on the experimental data, a good agreement has been found with the results and the well-known correlations in the literature. Also, it was obtained that increasing flow rate let to increase in Nusselt number. One of the most important results obtained is that the presence of MF offers up to 8.32% convective heat transfer enhancement compared with the absence of a MF. In addition, the constant MF applied externally to the flow is a key factor to control the convective heat transfer for such kind of geometry, which is widely used in thermal engineering systems.
Funding
The authors would like to thank the Scientific and Technological Research Council of Turkey (TUBITAK) for providing financial support for this study under the 217M978 project and Karabük University under the KBÜBAP-18-DR-185 scientific research project.
Disclosure statement
No potential conflict of interest was reported by the authors.
Nomenclature
DDiameter (m)
hAverage convective heat transfer coefficient (W/m2·°C)
kThermal conductivity (W/m°C)
LLength of the pipe (m)
µDynamic viscosity (kg/m.s)
NuAverage Nusselt number
q˝Heat flux (W/m2)
ReReynolds number
ρDensity (kg/m3)
TMF magnitude (Tesla)
TbBulk temperature of the working fluid (°C)
TinInlet temperature of the working fluid (°C)
ToutOutlet temperature of the working fluid (°C)
Tw Average temperature at the wall (°C)
xLocal axial length from the channel inlet
VAverage velocity of the working fluid (m/s)
MF Magnetic Field
FNF Ferro-nano-fluid
NFVC Nano-fluid Volume Concentraion