GEOMETRY OF THE FLASH DYNAMICS

The qualitative behavior of the dynamics of an adiabatic flash with constant volumes and pressure is studied. If the phase equilibria are thermodynamically stable, the ordinary differential balance equations describing the dynamics can be interpreted as a gradient system on a Riemannian manifold where the metric derives from the Hessian matrices of the entropies and where the potential is the entropy production. When the feed remains constant, such a geometric interpretation insures asymptotic stability and proves the convergence without sustained oscillations to the steady state where the entropy production is minimum.