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 o f a strongly shearing Lennard-Jones fluid in the limit of zero tempera ture gradient. Using nonequilibrium molecular-dynamics simulation meth ods, we find that the diagonal elements of the thermal-conductivity te nsor are independent of the strain rate gamma up to approximately gamm a = 1.0. At higher strain rates, the xx and yy elements increase weakl y with strain rate while the zz element decreases weakly. The xy and y x elements of the thermal-conductivity tensor decrease, initially line arly, with increasing strain rate from their equilibrium value of zero . These results are in agreement with conclusions obtained from symmet ry arguments.