Specific turbulence dissipation rate
From CFD-Wiki
The specific turbulence dissipation, is the rate at which turbulence kinetic energy is converted into thermal internal energy per unit volume and time. Sometimes the specific turbulence dissipation, , is also referred to as the mean frequency of the turbulence. This is mainly based on dimensional analysis. The SI unit of is .
There is no strict mathematical definition of the specific turbulence dissipation, (at least none known by the author, please add one here if you know it). Instead it is most often defined implicitly using the turbulence kinetic energy, , and the turbulence dissipation, :
Where is a model constant, most often set to:
Please note that some models/codes instead use a different definition without the model constant: