The pressurestrain model of this important class of engineering models
has been originally suggested by Launder et al. (1975). It can be written
as

(86) 
where that last term has been added by Gibson and Launder (1978) to
account for the effects of gravity in stratified fluids. This term is
identical to the last term in (53).
The new productionofanisotropy tensor is defined as

(87) 
Using the tensor relations

(88) 
(86) can be rewritten in the form

(89) 
Comparting with (53), the following relations can be estabilished:
,
,
,
,
, and
.
Gibson and Launder (1978) use a slightly different notation for the pressurescambling
model (59). Their model is somewhat simplified form of the model of
Jin et al. (2003), which can be written as

(90) 
Using the decomposition of the velocity gradient in its symmetric and anti
symmetric part, (56), the following parameter relation are evident:
,
,
,
,
.
Parameter values for this model are compiled in table 3. `GLNEW' denotes
the revised parameter set for the pressurestrain model given in Wilcox (1998) and
for the pressurebuoyancy gradient model in Zhao et al. (2001).
Karsten Bolding
20121228