Computes the values of the stability function defined in (46) in the logarithmic boundary-layer, , and in shear-free, spatially decaying turbulence, sf (see section 4.7.4).
is the value of in unstratified equilibrium flows, i.e. in the logarithmic wall region. It can be obtained from the relation , according to (80) written in the form
Algebraic Stress Models exhibit an interesting behaviour in unstratified, shear-free turbulence. Clearly, in the absence of shear, these models predict isotropic turbulence, , according to (61). This is a direct consequence of the assumption (60), implying an infinitely small return-to-isotropy time scale. Formally, however, the limit of the stability function for follows from (76) and the definitions given in sections 4.24-4.26. The limiting value is
Note that sfsf according to (78).
IMPLICIT NONEINPUT PARAMETERS:
integer, intent(in) :: turb_method integer, intent(in) :: stab_method integer, intent(in) :: scnd_methodREVISION HISTORY:
Original author(s): Lars Umlauf
Karsten Bolding 2012-12-28