Analysis Of Phonon Heat Conduction Based On Molecular Dynamics

Phonon heat conduction is an important process of heat transfer in solids,which has a significant impact on the thermal properties of materials.Further research on phonon heat conduction can help us better understand the thermal properties of materials,thereby optimizing their performance.This not only provides a theoretical basis and guidance for the design and preparation of new thermal materials,but also has broad academic value and application prospects in many disciplines.With the development of computer technology and numerical simulation methods,phonon heat conduction simulation methods based on Molecular Dynamics(MD)have been widely used.Unlike experimental and theoretical studies,MD simulation results provide detailed material structure information and thermodynamic properties.The Boltzmann Transport Equation(BTE)method and the Green Kubo Modal Analysis(GKMA)method are two widely used methods that can be combined with MD simulation for phonon heat conduction analysis.Both require the extraction of phonon features through dynamic matrices,and their analytical methods involve the second derivative of atomic force fields with respect to atomic displacements,which is not suitable for molecular dynamics models using complex multi body fields.The existing literature lacks a specific description of this critical step.In addition,there is also a lack of work on phonon heat conduction characteristics at different temperatures using the GKMA method in the literature.In this work,the numerical estimation method of dynamic matrix based on MD simulation proposed in recent years is combined with the GKMA and BTE phonon heat conduction analysis methods to construct a universal analysis framework that is independent of the force field form.Taking the Face-centered cubic(FCC)argon atomic crystal as an example,and combining the dispersion relationship results of the system in the literature,its feasibility and effectiveness are verified,Based on this,the dependence of thermal conductivity on phonon frequency and wavelength at different temperatures was calculated using this method.In addition,a comparative analysis of the calculation results based on the GKMA method combined with the short and long range heat transfer models is also conducted.