[sega]

Originally Posted by hadi

Hi to all,

I have another question, when i restart averaging do u think i should, set nuSgs boundary condition to zeroGradient, or i can keep the lastest values?
Because i was wondering if it might affect the results.
Do u think that rms values should be symmetric even if the values are not converged yet, since the fields are collapsed in streamwise and spanwise directions ?

Thanks in advance
Hadi

Hello.

I would like to catch up with this question.
I'm currently doing channel flow simulations in a square duct.
I was woundering under which conditions a zeroGradient boundary condition for nuSgs at the wall is justified?

S.

[BernhardGrieser]

Did someone already run perturbU for channels with OpenFOAM 1.7.1 ?
I have issues matching the libraries correctly when compiling with "wmake".

There's a few versions of perturbU around (e.g. 742, 4342, 3316). Their ./Make/options -files are different:

Version perturbU-742:
EXE_INC = \
-I$(LIB_SRC)/cfdTools/incompressible \
-I$(LIB_SRC)/cfdTools/lnInclude

Version perturbU-4342:
EXE_INC = \
-I$(LIB_SRC)/meshTools/lnInclude \
-I$(LIB_SRC)/finiteVolume/lnInclude

EXE_LIBS = \
-lmeshTools \
-lfiniteVolume

Version perturbU-3316:
EXE_INC = \
-I$(LIB_SRC)/finiteVolume/lnInclude \
-I$(LIB_SRC)/meshTools/lnInclude \
-I$(LIB_SRC)/cfdTools/incompressible \
-I$(LIB_SRC)/cfdTools/lnInclude

EXE_LIBS = \
-lfiniteVolume \
-lmeshTools


Can someone who's successfully running perturbU on OF171 post his options for me, please?

Best regards,
Bernhard

[stevenvanharen]

EXE_INC = \
-I$(LIB_SRC)/meshTools/lnInclude \
-I$(LIB_SRC)/finiteVolume/lnInclude


EXE_LIBS = \
-lmeshTools \
-lfiniteVolume

This works fine for me, but it appears you already have tried this.

[BernhardGrieser]

Thanks for posting, Steven!

I just tested your settings on my private computer as well. This time no error message appears after compiling, but the results are strange. Attached is a cut through of the flowfield of the spanwise component of U, which is the only component that has changed. My geometry is a simple squareDuct, divided into several blocks.

I changed various parameters within perturbUDict, but the outcome was always the same.

Which perturbU.C - file are you using in OpenFOAM-1.7.1? Maybe you can also post the content of yours.

Regards,
Bernhard

[stevenvanharen]

haha, that looks indeed strange

my perturbU works without a dictionary

I attached the C file. Good luck!

[HakikiCanakkaleli]

For those who would like to use this utility in OpenFOAM 2.2.x.
Many thanks for the utility.

[m.Chrsitiano]

Hello,

I want to do a 3d lock-exchange simulation. And I would like to set an initial pertubation in velocity. But how do I implement de perturbU for exemple in twoLiquidMixingFoam case?

Thank you for any replay, any answer would be very helpful!

[Shahr]

I am having difficulty for perturbing flow for Re_tau=180. It works perfectly for Re=395. My OF version is 2.3.x and I use the perturbU posted by HakikiCanakkaleli.

I tried to change the perturbU parameters too, but they don't work either. No matter what parameters I choose, the result U field is either very laminar-like or leads to laminar-like flow in say 50 time steps.

Any help in initialisation of Re_tau=180 flow is hugely appreciated.

[ari003]

Originally Posted by nzy102

Hi Marhamat:

Somehow I couldn't get converged results. The calcuated pressure gradient is way off from the analytical solution. I am trying to compare my results with kim's dns data and moser's les data. My setup is exactly same as channel395 except that I used different computational domain. The initial condition for u is generated using perturbU. I've be running this case for more than 20 flow through times. Do you have similar experience? Regarding perturbU, do I need to turn on bulk flow?

Ning

Hello Ning, could you please share how you ran that perturbU in the terminal? I'm getting repeated error stating Command not found despite proper installation.