Narrow Results

Molecular dynamics simulations technique is used to study the consolidation of two nanoparticles of Cu element. We have studied sintering processes of two nanoparticles at different temperatures. Two model systems with 4 and 10 nm diameter of particles are selected to study the sintering process of the two nanoparticles. Orientation effects on the physical properties of consolidation of two nanoparticles with respect to each other are investigated. Temperature effects on the consolidation of two nanoparticles are also studied. The order of the values obtained in the simulation for the constant volume heat capacity and latent heat of fusion is good agreement with the bulk results. Moreover, we have investigated the size effects on the consolidation of two different sizes of nanoparticles, that is, one particle of diameter with 10 nm is fixed while the other one is changing from 1 to 10 nm. Melting temperatures of the copper nanoparticles are found to be decreased as the size of the particle decreases. It is found that simulation results are compatible with the other theoretical calculations.

We present an application of the hybrid finite-difference Lattice-Boltzmann model, recently introduced by Lee and coworkers for the numerical simulation of complex multiphase flows.^1–4 Three typical test-case applications are discussed, namely Rayleigh–Taylor instability, liquid droplet break-up and coalescence. The numerical simulations of the Rayleigh–Taylor instability confirm the capability of Lee's method to reproduce literature results obtained with previous Lattice-Boltzmann models for non-ideal fluids. Simulations of two-dimensional droplet breakup reproduce the qualitative regimes observed in three-dimensional simulations, with mild quantitative deviations. Finally, the simulation of droplet coalescence highlights major departures from the three-dimensional picture.