Abstract:
Nanofluid is nanomaterials suspension in the base fluid. It possesses better thermal properties and has better potential for heat transport in different applications compared to conventional fluids, but the major concern is nanofluid stability and durability. In this study, nanofluid stability and thermal properties are evaluated for practical application. Titanium dioxide nanoparticles were synthesized using a chemical method and were characterized by scanning electron microscopy, energy dispersion X-ray spectroscopy and X-ray diffraction. Nanofluid was prepared using titanium dioxide particles and water by two steps method. Cetyl trimethyl ammonium bromide (CTAB) surfactant and probe ultrasonication were used to improve the stability of the nanofluid. sedimentation photo capturing and UV-Vis spectrophotometer was used for stability evaluation. Nanofluid viscosity was measured with viscometer and its variation was evaluated at different concentrations of the nanoparticles (0.05vol%, 0.1vol%, and 0.2 vol%) and temperatures (30 oC to 80 oC). This study further evaluates the variation of viscosity with shear rate (50 s-1 to 244 s-1) applied to the sample. The formation of the spherical shape and anatase phase along with small amount of rutile phase of titanium dioxide nanoparticles are confirmed by experimental results. The stability of the nanofluid was observed to be enhanced significantly by the addition of surfactants. The viscosity of the nanofluid was found to have a direct relation with particle loading and shear rate while it has an inverse relation with the temperature of the sample. The thermal conductivity was observed to have direct relation with the amount of particle loadings in the nanofluid.
