The assumptions required for deriving them are that the stress tensor, heat flux, energy, and entropy are only functions of density, absolute temperature, velocity, and the gradients of velocity and temperature.
The assumptions required for deriving them are that the stress tensor, heat flux, energy, and entropy are only functions of density, absolute temperature, velocity, and the gradients of velocity and temperature. A further requirement is that those dependencies must be linear in the gradient of temperature and velocity, at which point the balance and continuity equations are required. Adding to that the constitutive relations for the fluid yields, FTP, what famous nonlinear equations which completely describe fluid flow?
The assumptions required for deriving them are that the stress tensor, heat flux, energy, and entropy are only functions of density, absolute temperature, velocity, and the gradients of velocity and temperature.
Navier-Stokes equations