The Synchronized Molecular-Dynamics simulation which was recently proposed by
authors [Phys. Rev. X {\bf 4}, 041011 (2014)] is applied to the analysis of
polymer lubrication between parallel plates. The rheological properties,
conformational change of polymer chains, and temperature rise due to the
viscous heating are investigated with changing the values of thermal
conductivity of the polymeric liquid. It is found that at a small applied shear
stress on the plate, the temperature of polymeric liquid only slightly
increases in inverse proportion to the thermal conductivity and the apparent
viscosity of polymeric liquid is not much affected by changing the thermal
conductivity. However, at a large shear stress, the transitional behaviors of
the polymeric liquid occur due to the interplay of the shear deformation and
viscous heating by changing the thermal conductivity. This transition is
characterized by the Nahme-Griffith number Na which is defined as the ratio
of the viscous heating to the thermal conduction at a characteristic
temperature. When the Nahme-Griffith number exceeds the unity, the temperature
of polymeric liquid increases rapidly and the apparent viscosity also
exponentially decreases as the thermal conductivity decreases. The conformation
of polymer chains is stretched and aligned by the shear flow for Na<1, but
the coherent structure becomes disturbed by the thermal motion of molecules for
Na>1.Comment: 19 pages, 3 figures. arXiv admin note: substantial text overlap with
arXiv:1401.124
