The energy balance equations state conservation of the average carrier energies. In terms of the carrier temperatures and they can be written as

Here, and denote the energy relaxation times, while and are the energy fluxes.

The carrier thermal conductivities, and , are assumed to obey a generalized

(3.12) | |||

(3.13) |

The heat capacities and are usually neglected ().

Strictly speaking, the model described above in this subsection represents an energy
transport (ET) model. Such a model is obtained when in the course of deriving the
moment equations the average kinetic energy is consequently neglected against
the thermal energy, assuming that
. Since in the literature the terms *energy transport*
and *hydrodynamic transport* are often used synonymously, and since during
the development of *MINIMOS-NT* the term *hydrodynamic transport* was used,
this notation is retained throughout this work.

2001-02-28