  The Exergetic Port-Hamiltonian Systems modeling language combines a graphical
syntax inspired by bond graphs with a port-Hamiltonian semantics akin to the
GENERIC formalism. The syntax enables the modular and hierarchical
specification of the composition pattern of lumped and distributed-parameter
models. The semantics reflects the first and second law of thermodynamics as
structural properties. Interconnected and hierarchically defined models of
multiphysical thermodynamic systems can thus be expressed in a formal language
accessible to humans and computers alike. We discuss a composed model of the
Navier-Stokes-Fourier fluid on a fixed spatial domain as an example of an open
distributed-parameter system. At the top level, the system comprises five
subsystems which model kinetic energy storage, internal energy storage, thermal
conduction, bulk viscosity, and shear viscosity.
