THERMAL-CONDUCTIVITY OF A SHEARING FLUID

A recently derived Green-Kubo formula for the thermal conductivity of a shearing fluid has been used to calculate the thermal conductivity of a strongly shearing Lennard-Jones fluid in the limit of zero temperature gradient. Using nonequilibrium molecular-dynamics simulation methods, we find that the diagonal elements of the thermal-conductivity tensor are independent of the strain rate gamma up to approximately gamma = 1.0. At higher strain rates, the xx and yy elements increase weakly with strain rate while the zz element decreases weakly. The xy and yx elements of the thermal-conductivity tensor decrease, initially linearly, with increasing strain rate from their equilibrium value of zero. These results are in agreement with conclusions obtained from symmetry arguments.