Molecular Dynamics simulations are performed to calculate thermal conductivity of nanofluids and to understand the fundamental physics of the enhancement in experiments. Based on the analysis, excess potential energy of nanoparticles suspended in the liquid plays the major role on the enhancement.

The dependence of superlattice thermal conductivity on period length is investigated by molecular dynamics simulation. For perfectly lattice matched superlattices, a minimum is observed when the period length is of the order of the effective phonon mean free path. As temperature decreases and interatomic potential strength increases, the position of the minimum shifts to larger period lengths. ...

The thermal conductivities of quartz and the siliceous zeolites sodalite, faujasite and zeolite-A have been calculated using molecular dynamics simulations. The predicted thermal conductivities range over one order of magnitude at room temperature, and the quartz values are in reasonable agreement with the available experimental data. Evidence of phonon scattering is found by considering the la...

From three-dimensional linearized hydrodynamic equations, it is found that the heat conductivity is proportional to (Lx/(L 2 yL 2 z)) , where Lx, Ly and Lz are the lengths of the system along the x, y and z directions, and we consider the case in which Lx ≫ Ly, Lz. The necessary condition for such a size dependence is derived as φ ≡ Lx/(n L 5/4 y L 5/4 z ) ≫ 1, where φ is the critical condition...

We use nonequilibrium molecular dynamics simulations to study the adverse role of defects including isotopic impurities on the thermal conductivity of carbon nanotubes, graphene, and graphene nanoribbons. We find that even in structurally perfect nanotubes and graphene, isotopic impurities reduce thermal conductivity by up to one half by decreasing the phonon mean-free path. An even larger ther...

Using ab initio molecular dynamics, the atomic structure and transport properties of eutectic Ga-In and Ga-In-Sn are investigated. The Kubo-Greenwood (K-G) and the Ziman-Faber (Z-F) formulations and the Wiedemann-Franz (W-F) law are used for the electrical and electronic thermal conductivity. The species diffusivity and the viscosity are also predicted using the mean square displacement and the...

Both electron and phonon transport properties of single layer MoS2 (SLMoS2) are studied. Based on first-principles calculations, the electrical conductivity of SLMoS2 is calculated by Boltzmann equations. The thermal conductivity of SLMoS2 is calculated to be as high as 116.8 Wm(-1) K(-1) by equilibrium molecular dynamics simulations. The predicted value of ZT is as high as 0.11 at 500 K. As th...

Transport properties of liquid methanol and ethanol are predicted by molecular dynamics simulation. The molecular models for the alcohols are rigid, nonpolarizable, and of united-atom type. They were developed in preceding work using experimental vapor-liquid equilibrium data only. Self- and Maxwell-Stefan diffusion coefficients as well as the shear viscosity of methanol, ethanol, and their bin...

A nonequilibrium molecular dynamics (NEMD) method using stochastic energy injection and removal as uniform heat sources and sinks is developed to calculate the thermal conductivity. The stochastic energy is generated by a Maxwell function generator and is imposed on only a few individual molecules each time step. The relaxation of the thermal perturbation is improved compared to other NEMD algo...

We report on molecular dynamics studies of heat flow in superlattices. The computer simulations are performed using classical mechanics with periodic boundary conditions. The heat flow is in the direction normal to the layers. We have studied the variation of the conductivity with the repeat distance and the effect of interfacial roughness. We discuss the relation of these results to experiment...