PHOENICS makes provision for the following low-Reynolds-number turbulence models:
This feature, here called LRNM (standing for Local Reynolds Number Modification), is provided in subroutine GXENUT, where it is activated by setting IENUTA = 6 or 9.
The LRNM turbulent-kinematic-viscosity, νt, formula for INEUTA=6 is:
νt = νt,nom * amin1(1.0 , (A * Ret)B)
where: Ret=νt,nom/νl = the Local Reynolds Number (LRN); νt,nom = nominal (high-Reynolds-number) value of νt νl = laminar viscosity; A = ENUTA; B = ENUTB.
Suitable values for A and B may be 0.05 and 4.0.
The LRNM turbulent-viscosity formula for IENUTA=9 is:
vist = vist_nom for ENUTA * LRN < 1.0, and vist = 0.0 for ENUTA * LRN < 1.0
A suitable value for ENUTA may be 0.05 .
Relevant "help-file" entries are :- DISWAL, EL1, EL1A, EL2, EL2A, ENUT, ENUTA, GENK, PRT, TURBUL, TURMOD.
Relevant "Encyclopaedia" entries include: CHEN-Kim KE-EP turbulence model, K-Omega turbulence model, LAM-Bremhorst KE-EP turbulence model, LVEL turbulence model, RNG KE-EP turbulence model, TWO-Layer KE-EP turbulence model, VAN-Driest damping model.