vanDriestDelta documentation - the default value of Cdelta
Hi,
Please see the two remarks below for vanDriestDelta
implementation:
-
As can be seen in
vanDriestDelta.C
lines: [87-91], the van Driest function formulation (doi: 10.2514/8.3713, 1956) is slightly different from its original form. A minimum switch was introduced by de Villiers (http://bit.ly/1unTPaB, 2006) as shown in pages: [124, 260]. IMHO, it would be nice of you as well as useful to some users if his heuristic modification/work is noted and cited in the Extended Code Guide, which is currently absent. -
In addition,
vanDriestCoeffs
'sCdelta
is (most of the time) kept equal to0.158
by default in the tutorials as can be found intutorials/incompressible/pimpleFoam/LES/channel395DFSEM/constant/turbulenceProperties
of v1712, for instance. However, as shown in de Villiers, the unnumbered equation in page 260,Cdelta
is actuallyCs
. This may suggest, at least forchannel395DFSEM
tutorial, thatCdelta
needs to equateCdelta=Cs=0.065
rather than0.158
. Not sure if it is of practical importance though. Just an observation :)
Kind regards,