Question

In the low Reynolds number turbulence models, the first internal grid point is placed in the ___________

(a) log-law layer

(b) buffer layer

(c) inertial sub-layer

(d) viscous sub-layer

I have been asked this question during an interview.

The origin of the question is Turbulence Modelling in chapter Turbulence Modelling of Computational Fluid Dynamics

Answer 1

Correct choice is (d) viscous sub-layer

The explanation is: It is difficult to model the flow in the buffer layer. So, the low Reynolds number models place the first internal grid point in the viscous sub-layer and the high Reynolds number models place it in the inertial sub-layer skipping the buffer layer.