2 research outputs found
Numerıcal ınvestıgatıon of lamınar forced convectıon and entropy generatıon of fe3o4/water nanofluıds ın dıfferent crosssectıoned channel geometrıes
In this study, forced convection of nanofluid flow in various channel geometries with a hydraulic diameter of
16 mm and length of 1.5 m under laminar flow condition has been investigated numerically. Constant heat flux of 6
kW/m2 has been applied on to the surfaces of the channels. Fe3O4/water nanofluid has been used in the analyses to
enhance the convective heat transfer of the base fluid. Analyses have been performed for Reynolds numbers between
500≤Re≤2000, and for volume concentrations of nanoparticles between 1% and 5% in cylindrical, square, rectangle,
and triangle cross-sectioned channel geometries. The finite volume discretization method has been used to solve the
governing equations. The effects of some parameters; Reynolds number, nanoparticle volume fractions, channel
geometries on the average Nusselt number, Darcy friction factor and entropy generation have been investigated in
detail. The results indicate that nanofluid offers further convective heat transfer enhancement according to base fluid
and cylindrical cross-sectioned channel gives the best heat transfer performance among other cross-sectioned channel
geometries. Using water as a working fluid, cylindrical cross-sectioned channel geometry gives the highest heat
transfer rate among other channel geometries, whereas triangle one gives the lowest. Cylindrical cross-sectioned
channel geometry offers up to 77.6% enhancement compared to triangle cross-sectioned channel geometry for the
same hydraulic diameter and same heat flux. However, triangle cross-sectioned channel geometry has highest
convective heat transfer increment ratio (4.12%) for changing working fluid as water to nanofluid. Also, some new Nu
correlations based on the channel geometries and nanoparticle volume fractions were proposed in the present study