On Thermal Conductivity And Viscosity Of Viscoelastic-fluid-based Nanofluids

For the sake of getting a novel heat transfer fluid with high heat transferproperties as well as turbulent drag reducing abilities, we have firstly preparedviscoelastic-fluid-based nanofluids (VFBN) using aqueous solution of cetyltrimethylammonium chloride/sodium salicylate (CTAC/NaSal, NaSal is as counterion.) asviscoelastic base fluid and carbon nanotubes (CNTs) as nanoparticles.Secondly, the thermal conductivity and shear viscosity of the prepared VFBNwith variation of particle volume fraction, temperature and concentration of basefluid were experimentally investigated. The measured results show that the thermalconductivity of the tested VFBN is significantly higher than corresponding basefluids and increases with increasing particle volume fraction and temperature. Then,the rheological results of VFBN with MWCNTs shows a non-Newtonian behaviorand its viscosity increases with the increase of particle volume fraction and decreaseof temperature.Furthermore, by means of micro-incised method, two thermal conductivitymodels for nanofluids with spherical particles and with CNTs have been proposed atlast. The comparisons between measured results and predictions of new model onthermal conductivity of VFBN were also exhibited, among which the predictionsmatch the temperature and volume fraction changed thermal conductivities prettywell, with a maximum deviations of2.94%, and with the established new thermalconductivity model of nanofluid we simply study the relationship between thermalconductivity and varieties of physical parameters, which lays a foundation for thefuture research.