Shear viscosity of the Lennard-Jones chain fluid in its gaseous, supercritical, and liquid states

Guillaume Galliero (1) , Christian Boned (1)

1 TEFC - Thermodynamique et Energétique des fluides complexes

Extensive nonequilibrium molecular dynamics (NEMD) simulations have been carried out in order to estimate the Newtonian shear viscosity of a fluid composed of short chains, up to 16 segments, of jointed spheres (Lennard-Jones chain (LJC)) over a large range of thermodynamic conditions. Using the NEMD results, it is shown that the zero-density contribution decreases with the chain length for a given temperature and is simply proportional to N−1/2, where N is the number of spheres composing the chain. In addition, it has been noticed that the residual shear viscosity is proportional to the chain length. Then, using these results, a relation is proposed to correlate the shear viscosity of the LJC fluid using the LJ fluid, the monomer, as a reference. It is shown that this correlation is able to provide an excellent estimation of the LJC fluid viscosity compared to NEMD results for N<16 over the domain 0

Mots clés: number͑s͒: 66; 20; Cy; 02; 70; Ns

Domaines: Chimie-Physique [physics.chem-ph]

Guillaume Galliero, Christian Boned. Shear viscosity of the Lennard-Jones chain fluid in its gaseous, supercritical, and liquid states. Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, 2009, 79 (021201), pp.1-9. ⟨10.1103/PhysRevE.79.021201⟩. ⟨hal-00370702⟩