7.9 Low-Re k-epsilon models
There are many low- turbulence models for CFD simulations where the cells near the solid walls are suﬃciently thin to resolve the ﬂow through the viscous sub-layer.
Among them are several low- models based on Eq. (7.1 ) and Eq. (7.2 ) with additional corrections , , and :
Launder and Sharma subsequently presented13 the model with a modiﬁed function and the more established coeﬃcients listed in Eq. (7.3 ).
The resulting model became known as the Launder-Sharma model.14 It is arguably the most popular low- model today.
The ﬁrst notable modiﬁcation to the standard model is (sometimes denoted “”) in Eq. (7.29 ). It is the dissipation rate at the wall (), see ﬁgure, Sec. 7.7 , calculated by
- ﬁxed value ;
- ﬁxed value .
The next signiﬁcant modiﬁcation is the function
The extra term in Eq. (7.30) is a follows, designed so that matches its recognised peak value within the buﬀer layer: