Experimental investigation and proposed correlations for temperaturedependent thermal conductivity enhancement of ethylene glycol based nanofluid containing ZnO nanoparticles

Experimental study of effective thermal conductivity of ZnO/EG nanofluid is presented in thisresearch. The nanofluid was prepared by dispersing Zno nanoparticles in ethylene glycol using asonicator and adding surfactant. Ethylene glycol based nanofluid containing ZnO nanoparticlewith a nominal diameter of 18 nm at different solid volume fractions (very low to high) atvarious temperatures was examined for the investigation. The thermal conductivity of nanofluidsis experimentally measured with THW method and it is found that the thermal conductivity ofnanofluids increase with the nanoparticle volume concentration and temperature. Also, based onexperimental values of thermal conductivity of nanofluid, three experimental models areproposed to predict thermal conductivity of nanofluids. The proposed models show reasonablyexcellent agreement with our experimental results.