Characteristics of forced convection heat transfer of Co0.5Zn0.5Fe2O4 during laminar flow in a tube
Yijie Tong, Areum Lee and Honghyun Cho
The convective heat transfer characteristics of a Co0.5Zn0.5Fe2O4 nanofluid in the laminar flow region based on various concentrations are measured experimentally. The results indicate that the convective heat transfer coefficient increases with the concentration. The maximum heat transfer improved by 24.7% for the CCo0.5Zn0.5Fe2O4 nanofluid at concentration 0.2wt% when the Reynolds number (Re) is 1600, compared with that of the base fluid (water/ethylene glycol (EG) = 80:20). Furthermore, the heat transfer improved by 3.6%, 16.2%, 22.5%, and 32.4% at concentrations of 0.025wt%, 0.05wt%, 0.1wt%, and 0.2wt%, respectively, when Re is 1400, compared with that of the base fluid (water/EG = 80:20). The convective heat transfer coefficient ratio of the Co0.5Zn0.5Fe2O4 nanofluid varied from 1.04 to 1.35. This means that the Co0.5Zn0.5Fe2O4 nanofluid had a larger heat transfer coefficient than the base fluid. Additionally, compared with that of the base fluid (water/EG = 80:20), the pressure drop of the Co 0.5 Zn 0.5 Fe 2 O 4 nanofluid increased by 1.52%, 4.33%, 5.49%, and 7.32% at concentrations 0.025wt%, 0.05wt%, 0.1wt%, and 0.2wt%, respectively, when Re is 1600.
Keywords: CCo0.5Zn0.5Fe2O4 Fe 2 O 4 ; Nanofluid; Thermal conductivity; Viscosity; Convective heat transfer coefficient; Pressure drop