Port contact systems for irreversible thermodynamical systems

In this paper we propose a definition of control contact systems, generalizing input-output Hainiltonian systems, to cope with models arising from irreversible Thermodynamics. We exhibit a particular subclass of these systems, called conservative, that leaves invariant some Legendre submanifold (the geometric structures associated with thermodynamic properties). These systems, both energy-preserving and irreversible, are then used to analyze the loss-lessness of these systems with respect to different generating functions