Thermodynamics of Fluids Under Flow

The thennodynamics of fluids under shear flow is an active and very challenging topic in modem non-equilibrium thennodynamics and statistical mechanics. The interest is both theoretical and practical. From the theoretical point of view, the influence of the shear effects on the thennodynamic potentials requires the fonnulation of thennody­ namic theories beyond the local-equilibrium hypothesis; this is a field with many open questions, which fosters an active dialogue between macroscopic and microscopic theo­ ries, the latter based either on the kinetic theory of gases or on computer simulations of gases or liquids. Furthennore, it also requires an open discussion between thermodyna­ mics and hydrodynamics, because some of the phenomena observed may have a purely thennodynamic origin (due to the modification of some equations of state) or a purely in general there will be an interplay of both thennodynamic hydrodynamic origin, but and hydrodynamic effects. To clarify the fonnulation of a non-equilibrium thennody­ namics beyond the local-equilibrium regime, and its relationship with microscopic theories and with hydrodynamic theories currently represents an important frontier. From the practical point of view, many situations of technological interest are present in fluid systems under flow. Indeed, the modification of the thennodynamic equations of state for the chemical potential imply modifications in the phase diagram of substances in non-equilibrium states, or on the conditions of chemical equilibrium and stability.