Response to “Comment on ‘Molecular simulation and continuum mechanics study of simple fluids in nonisothermal planar Couette flows’ ” [J. Chem. Phys. 111 , 10730 (1999)]

Abstract

This response clarifies some of the issues raised in the comment by Todd et al. It is emphasized that at the typical shear rates currently used in nonequilibrium molecular-dynamics simulations, fluids undergo significant viscous heating. While artificial thermostats can be used to keep the temperature constant, we have shown that actual confined fluids at high shear rates are unable to dissipate heat at the rate required to avoid viscous heating. This raises questions as to the relevance of thermostating an entire confined fluid subject to a high shear rate; such a situation is simply not physically realizable. In our work we argue that removing heat through the walls of a confined system provides a better representation of reality.