Open Access

Thermodynamic modeling, energy equipartition, and nonconservation of entropy for discrete-time dynamical systems

  • Wassim M Haddad1Email author,
  • Qing Hui1,
  • Sergey G Nersesov1 and
  • Vijaysekhar Chellaboina2
Advances in Difference Equations20052005:248040

Received: 19 November 2004

Published: 27 September 2005


We develop thermodynamic models for discrete-time large-scale dynamical systems. Specifically, using compartmental dynamical system theory, we develop energy flow models possessing energy conservation, energy equipartition, temperature equipartition, and entropy nonconservation principles for discrete-time, large-scale dynamical systems. Furthermore, we introduce a new and dual notion to entropy; namely, ectropy, as a measure of the tendency of a dynamical system to do useful work and grow more organized, and show that conservation of energy in an isolated thermodynamic system necessarily leads to nonconservation of ectropy and entropy. In addition, using the system ectropy as a Lyapunov function candidate, we show that our discrete-time, large-scale thermodynamic energy flow model has convergent trajectories to Lyapunov stable equilibria determined by the system initial subsystem energies.

Authors’ Affiliations

School of Aerospace Engineering, Georgia Institute of Technology
Department of Mechanical, Aerospace and Biomedical Engineering, The University of Tennessee


© Haddad et al. 2005