Question

The SGS model uses _________ to reduce the sub-grid-scale eddy viscosity near the wall.

(a) van Karman’s constant

(b) van Driest damping

(c) wall function

(d) Leonard stresses

I have been asked this question by my college director while I was bunking the class.

Question is from Turbulence Modelling in section Turbulence Modelling of Computational Fluid Dynamics

Answer 1

Right choice is (b) van Driest damping

Explanation: The purpose of the van Driest damping is to reduce the sub-grid-scale eddy viscosity near the wall in the SGS models. An alternative method is to reduce the eddy viscosity when the Reynolds number becomes small.