Direct effect of nanoparticles on the thermal conductivity of CuO-water nanofluid in a phase transition phenomenon using molecular dynamics simulation

摘要

The thermal behavior of CuO-water nanofluid is examined on an aluminum surface. The dimensions of simulation boxes are 70 x 70 x 30 angstrom(3), 60 x 60 x 30 angstrom(3), and 50 x 50 x 30 angstrom(3), with the corresponding number of atoms of 104,351, 123,958, and 145,980. Thermal conductivities of fluid and nanofluid are calculated using the Green-Kubo formula. Molecular dynamics simulation results confirm the direct effect of nanoparticles on the values of thermal conductivities of fluid and nanofluid. The value of 0.59 Wm(-1) K-1 is obtained for the thermal conductivity of water. But adding three CuO nanoparticles into the water increases this value to 0.85 Wm(-1) K-1. The same effect is observed on the thermal behavior of nanofluid upon increasing the size of CuO nanoparticles that raises the value of the thermal conductivity of nanofluid to 0.99 Wm(-1) K-1. The heat flux is increased by adding the nanoparticles into the base fluid; thereby, the phase transition (evaporation) occurs in fewer time steps.