NUMERICAL STUDY OF HEAT-TRANSFER ENHANCEMENT OF HOMOGENEOUS WATER-Au NANOFLUID UNDER NATURAL CONVECTION

摘要

A numerical analysis is performed to examine the heat transfer of colloidal dispersions of Au nanoparticles in water (Au nanofluids). The analysis used a two-dimensional enclosure under natural convection heat-transfer conditions and has been carried out for the Rayleigh number in the range of 10~3 ≤ Ra ≤ 10~5, and for the Au nanoparticles' volume-fraction range of 0 ≤ ψ ≤ 0.10. We report highly accurate numerical results indicating clearly that the mean Nusselt number is an increasing function of both Rayleigh number and volume fraction of Au nanoparticles. The results also indicate that a heat-transfer enhancement is possible using nanofluids in comparison to conventional fluids. However, low Rayleigh numbers show more enhancement compared to high Rayleigh numbers.