Long-range boundary effects in simple fluids

We discuss long-range boundary effects in simple two- or three-dimensional fluids. These boundary effects are due to the existence of long-range correlations in nonequilibrium fluids and can be computed either by means of kinetic theory or phenomenological mode-coupling theories. In particular, we use kinetic theory to compute the stress tensor and heat flux vector for a fluid in a nonequilibrium steady state in a finite geometry and show that both the effective shear viscosity and effective heat conductivity have contributions due to the walls of the container that influence the behavior of the system far into the fluid. We also show that the mechanocaloric effect is present in the bulk of a three-dimensional fluid and that there are normal stresses in a fluid whenever the temperature gradient is nonzero.Work performed under National Science Foundation grant No. CHE 77-16308.