A state of a thermodynamic system which is in thermal, mechanical, and chemical equilibrium.
Particularly in fluid dynamics it means that:
| the fluid temperature is constant at any moment of time t and spatial location {\bf r} = (x,y,z) of a fluid flow | ||
| the fluid pressure is constant at any moment of time t and spatial location {\bf r} = (x,y,z) of a fluid flow | ||
| fluid density is a function of pressure p and temperature T only | ||
| fluid viscosity is a function of pressure p and temperature T only | ||
| fluid thermal conductivity is a function of pressure p and temperature T only | ||
| fluid isobaric specific heat capacity is a function of pressure p and temperature T only | ||
| fluid Joule–Thomson coefficient is a function of pressure p and temperature T only | ||
| The Gibbs free energy is at minimum |