An investigation of silicon carbide-water nanofluid for heat transfer applications

Thermal conductivity and mechanical effects of silicon carbide nanoparticles uniformly dispersed in water were investigated. Mean size of SiC particles was 170 nm with a polydispersity of ∼30% as determined from small-angle x-ray scattering and dynamic light scattering techniques. Room temperature viscosity of the nanofluids ranged from 2 to 3 cP for nominal nanoparticle loadings 4–7 vol %. On a normalized basis with water, viscosity of the nanofluids did not significantly change with the test temperature up to 85 °C. Optical microscopy of diluted nanofluid showed no agglomeration of the nanoparticles. Thermal conductivity of the fluid was measured as a function of the nominal nanoparticle loading ranging from 1 to 7 vol %. Enhancement in thermal conductivity was approximately 28% over that of water at 7 vol % particle loadings under ambient conditions. Enhancements in thermal conductivities for the nanofluids with varying nanoparticle loadings were maintained at test temperatures up to 70 °C. Results of thermal conductivity have been rationalized based on the existing theories of heat transfer in fluids. Implications of using this nanofluid for engineering cooling applications are discussed.