What do we need to describe a - simple - fluid locally?
All quantities depend on space
Macroscopic bulk velocity
- Two thermodynamic quantities, e.g.
- temperature and pressure
- or mass density and internal energy
- LTE: two thermodynamic quantities are sufficient to describe the local
of the fluid completely:
element composition, ionization, occupation numbers, microscopic velocity distribution,
- we do not need to look at the
atomic level: we have a continuous fluid.