Weakly and strongly consistent formulations of irreversible processes.
If time-evolution equations are formulated in terms of thermodynamic building blocks, two possibilities arise to judge the consistency of models: By the properties of the building blocks (strong or structural consistency), or solely by the implied evolution equations (weak or dynamic consistency). We propose a straightforward procedure to check for strong consistency by means of the eigenvalues and eigenmodes of the linearized equations, which is related to establishing a fluctuation-dissipation theorem. By applying the general ideas to hydrodynamics, we clarify the role of the controversial diffusion terms in hydrodynamic equations.
Ottinger
Hans Christian
HC
ETH Zürich, Department of Materials, Polymer Physics, HCI H 543, CH-8093 Zürich, Switzerland. hco@mat.ethz.ch