The computational study of microchannel thickness effects on H<inf>2</inf>O/CuO nanofluid flow with molecular dynamics simulations

Abstract

Microchannels are promising structures for the different processes such as mass and heat transfer processes. Previous researches indicated the atomic behavior of nanofluids in these structures improved appreciably. In the current numerical study, the atomic behavior of H2O-CuO nanofluid inside Pt microchannel is described using Molecular Dynamics simulation. The results are reported by calculating physical properties such as temperature, total energy, density, velocity, temperature profile, and aggregation time. In our simulations, H2O-CuO nanofluid inside Pt microchannel is represented by Universal Force Field, TIP4P, and Embedded Atom Model. The simulation results show that the total energy of atomic structures converged to −509910 eV value after 10 ns. This calculation estimated the atomic stability of structures. Also, simulations predicted microchannel thickness is an important parameter for nanofluid flow. By increasing microchannel thickness, the absorption force between Pt atoms and nanofluid particles increases. Numerically, by increasing microchannel thickness to 15, the maximum density, velocity, and temperature profiles reach 1.23 g/cm3, 0.0065 Å/ps, and 264 K, respectively. Furthermore, by microchannel thickness increasing from 5 to 15, CuO nanoparticles’ aggregation time and potential energy increase from 1.32 ns and −659328 eV to 2.11 ns and −721583 eV. Physically, because of the amplitude of the atomic displacement, this atomic process occurs and decreases with the enlargement of the atomic layers. The movement atomic of various particles of H2O/CuO nanofluid increases by microchannel walls thickening and nanoparticles aggregation phenomenon occur in higher time.