ABSTRACT
Irreversibilities were introduced in Section 9.7 with the examples of heat conduction and friction. The energy fluxes in these cases are analogous to the other power flows considered, in the sense that they can be represented by simple bonds with a single effort and a single flow. Mass transfer complicates the energy flux, however; a new convection bond is introduced in Section 11.1 to address this. The bond has two efforts and a single flow. It represents the entropy fluxes as well as the mass flows and thereby accounts for the thermodynamic availability as well as the conservation of energy. Implementation for heat interactions and junctions for convection bonds is given in Section 11.2. Steady-state analysis can be carried out at this point, as illustrated in Section 11.3, analogous to the steady-state analysis of simple systems in Chapter 2 and parts of later chapters.
