Molecular Dynamics Simulation of Heat Transfer during Quenching in CNT Nanofluids

Nanofluids exhibit superior thermal properties to conventional fluid and particle-fluid suspensions and show a great potential as quenching media for quench hardening of steel components. The heat transfer mechanism in nanofluid is very complex and unclear. In this paper, molecular dynamics (MD) simulation method is used to theoretically study the heat transfer from a metal surface at different temperatures to a water-based nanofluid with functionalized carbon nanotubes (FCNTs). To model the quenching process, an initial temperature jump between the nanofluid and an iron slab is employed, and non-equilibrium molecular dynamics (NEMD) simulations are performed. The MD results reveal the heat transfer process in the initial stage of quenching and at the first moment of contact of a liquid nanofluid with a hot metal surface. The thermodynamics and transport properties of the nanofluid and the heat transfer characteristics are discussed with the atomistic details of the interactions of the FCNT with the iron atoms and the water molecules.