The term 
, representing the production of turbulence kinetic energy, is modeled
identically for the standard, RNG, and realizable 
-
models. From the exact equation for the transport of 
, this term may be defined as
 | (4–60) |
To evaluate 
in a manner consistent with the Boussinesq hypothesis,
 | (4–61) |
where 
is the modulus of the mean rate-of-strain tensor, defined as
 | (4–62) |
Important: When using the high-Reynolds number 
-
versions, the effective viscosity 
is used in lieu of 
in Equation 4–61. The coefficient 
has a default value of 1 and can be accessed via the rpvar
'coeff-ke-mu-prod.