Invalidity of Molecular Dynamics in Heat Transfer

Abstract

Molecular Dynamics (MD) simulations based on classical statistical mechanics always allow the atom to have thermal heat capacity. Quantum mechanics (QM) differs in that the heat capacity of atoms in submicron nanostructures vanishes. Nevertheless, MD simulations of heat transfer in discrete nanostructures are routlinely performed and abound in the literature. Not only are discrete MD sumultions invalid by QM, but give unphysical results, e.g., thermal conducitvity in nanofluids is found to exceed standard mixing rules while in solid metal films depends on thickness. QM negates the heat capacity of atoms in discrete nanostructures, thereby precluding the usual conservation of absorbed electromagnetic (EM) energy by an increase in temperature. Instead, conservation proceeds by QED inducing the absorbed EM energy to create non-thermal EM radiation inside the nanostructure that by the photoelectric effect chargea the nanostructure, or is emitted to the surroundings. QED stands for quantum electrodynamics. Unphysical results occur because QED induced radiation is not included in the nanoscale heat balance, but if included physical results for discrete nanostructures are found. Examples of unphysical MD simulatons are presented. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35192