Question

Represent the turbulent dynamic viscosity in terms of k and ω.

(a) ρ ω/k

(b) ρ k/ω

(c) ρ k^2/ω

(d) ρ ω/k^2

The question was posed to me in semester exam.

Enquiry is from Turbulence Modelling topic in section Turbulence Modelling of Computational Fluid Dynamics

Answer 1

Right option is (b) ρ k/ω

The best explanation: The turbulent dynamic viscosity is

μt = ρϑl

Where,

ρ → Density of the flow

ϑ → Length scale of the large eddies

l → Length scale of the small eddies

Replacing with the k and ω equivalents,

\(μ_t=\rho×\sqrt{k}×\frac{\sqrt{k}}{\omega}\)

\(μ_t=\rho×\frac{k}{\omega}\).