Question

Turbulence problems particularly depend on this term of the Navier-Stokes equations. Which is that term?

(a) Rate of change term

(b) Convection term

(c) Diffusion term

(d) Source term

The question was asked in homework.

I'm obligated to ask this question of Navier Stokes Equation topic in section Governing Equations of Fluid Dynamics of Computational Fluid Dynamics

Answer 1

Correct answer is (c) Diffusion term

The explanation is: Turbulence is caused by abrupt changes in velocities perpendicular to the flow. This, in turn, can be given in viscosity terms. Diffusion term of the Navier-Stokes equations holds the viscosity terms. So, without diffusion terms, we cannot model turbulence.