The phenomenon of heat flux bifurcation inside a porous medium is analyzed by studying the convective heat transfer process within a channel partially filled with a porous medium under Local Thermal NonEquilibrium (LTNE) conditions. Either the thermal dispersion effect or the inertial effect is considered in the physical model. Exact solutions are derived for both the fluid and solid temperatur...

We developed a multiscale approach to explore the effective thermal conductivity of polycrystalline graphene sheets. By performing equilibrium molecular dynamics (EMD) simulations, the grain size effect on the thermal conductivity of ultra-fine grained polycrystalline graphene sheets is investigated. Our results reveal that the ultra-fine grained graphene structures have thermal conductivity on...

A recently introduced particle-based model for fluid flow, called stochastic rotation dynamics, can be made Galilean invariant by introducing a random shift of the computational grid before collisions. In this paper, it is shown how the Green-Kubo relations derived previously can be resummed to obtain exact expressions for the collisional contributions to the transport coefficients. It is also ...

The thermal conductivity of solid argon at high-pressure (up to 50 GPa) and high-temperature (up to 2000 K) has been calculated by equilibrium molecular dynamics simulations using the Green-Kubo formalism and an exponential-6 interatomic potential. A simple empirical expression is given for its pressure and temperature dependence. The results are compared with predictions based on kinetic theor...

During thermal oxidation of binary amorphous AlxZr1-x solid solutions over wide alloycomposition (0.26 ≤ x ≤ 0.68) and oxidation-temperature (350 °C – 560 °C) ranges, a single amorphous ternary oxide phase of well-defined stoichiometry, (Al0.33Zr0.67)O1.83, emerges. The composition of this unexpectedly stoichiometric ternary amorphous oxide phase, that develops instead of the crystalline oxide ...

This paper provides a comprehensive study on the heat transfer and entropy generation rates in a channel partially filled with a porous medium and under constant wall heat flux. The porous inserts are attached to the walls of the channel and the system features internal heat sources due to exothermic or endothermic physical or physicochemical processes. Darcy-Brinkman model is used for modellin...

In a recent letter (C. Giraudet et al., EPL 111, 60013 (2015)) we reported preliminary data showing evidence of a slowing-down of non-equilibrium fluctuations of the concentration in thermodiffusion experiments on a binary mixture of miscible fluids. The reason for this slowing-down was attributed to the effect of confinement. Such tentative explanation is here experimentally corroborated by ne...