What is the formula to define the turbulence kinetic energy and turbulence dissipation rate? I am using the k-epsilon and VOF model? Thanks for any suggestion.

Hi,

a good guess is:

k = 1.5 * (U * TI)^2 [m^2/s^2]

eps = Cmu^0.75 * (k^1.5 / (0.07 * L)) [m^2/s^3]

where

U is the average (reference) velocity [m/s]

TI is the turbulent intensity which depends on the case (e.g. = 0.10 means turbulence that velocity turbulent fluctuations have an aplitude which is 10% of the average velocity)

Cmu = 0.09 is a constant

L is a characteristic dimension which depends on the case (e.g. tube diameter) [m]

I hope this helps.

Cheers

Maurizio