Question

Which of these models is a hybrid of LES and RANS?

(a) DNS model

(b) DES model

(c) WALE model

(d) RNG – LES model

I had been asked this question during an online exam.

This interesting question is from Turbulence Modelling topic in chapter Boundary Layers, Laminar & Turbulent Boundary Layers, Navier Stokes Solutions of Aerodynamics

Answer 1

The correct choice is (b) DES model

The best I can explain: DES model is a hybrid of LES and RANS model and makes use of advantages of both. For treating near –  wall regions, DES works like the RANS model and for rest of the region, it works as the LES model.