Contribution of inter- and intramolecular energy transfers to heat conduction in liquids.
Contribution of inter- and intramolecular energy transfers to heat conduction in liquids.
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DOI：
10.1063/1.2821963
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发表时间：
2008-01
期刊：
影响因子：
--
通讯作者：
D. Torii;T. Nakano;T. Ohara
中科院分区：
文献类型：
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作者：
D. Torii;T. Nakano;T. Ohara
本文将最初由欧文和柯克伍德[J.Chem.Phys.18，817（1950）]导出的两体势的热流分子动力学表达式推广到多体势系统。原公式由一个动力学部分和一个潜在的部分，和后一项被发现在本研究中被表示为从系统中定义的所有多体势的贡献的总和。讨论了多体势定义的一组位置之间的能量转移，并通过每个位置的动能由于势的增加率来评估，并且其在系统中所有势上的积累被示出为构成广义表达式的势部分。对液体正辛烷进行了分子动力学模拟，以证明本研究中获得的新表达式的适用性，以测量热通量，并阐明分子间和分子内势对热传导的贡献。
The molecular dynamics expression of heat flux, originally derived by Irving and Kirkwood [J. Chem. Phys. 18, 817 (1950)] for pairwise potentials, is generalized in this paper for systems with many-body potentials. The original formula consists of a kinetic part and a potential part, and the latter term is found in the present study to be expressible as a summation of contributions from all the many-body potentials defined in the system. The energy transfer among a set of sites for which a many-body potential is defined is discussed and evaluated by the rate of increase in the kinetic energy of each site due to the potential, and its accumulation over all the potentials in the system is shown to make up the potential part of the generalized expression. A molecular dynamics simulation for liquid n-octane was performed to demonstrate the applicability of the new expression obtained in this study to measure the heat flux and to elucidate the contributions of inter- and intramolecular potentials to heat conduction.