Question

The stress term \(\rho\overline{u_i^{‘}u_j^{‘}}\)is called as ____________

(a) Filter Reynolds stress

(b) LES Reynolds stress

(c) Reynolds stress

(d) Sub-Reynolds stress

I have been asked this question in an internship interview.

Origin of the question is Turbulence Modelling topic in chapter Turbulence Modelling of Computational Fluid Dynamics

Answer 1

Correct answer is (b) LES Reynolds stress

The best explanation: As the term resembles the Reynolds stress term, it is called the LES Reynolds stress term. This is modelled using Sub-Grid-Scale models, a special type of turbulence model used for these stresses.