CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   OpenFOAM (http://www.cfd-online.com/Forums/openfoam/)
-   -   I want to observe karman vortex by pimplefoam (http://www.cfd-online.com/Forums/openfoam/112454-i-want-observe-karman-vortex-pimplefoam.html)

wes1204 January 29, 2013 07:31

I want to observe karman vortex by pimplefoam
 
Hi everyone.
first of all, I am sorry that I am not good in english.

I am a newbie in Openfoam and CFD.
I want to observe vortex created by pimplefoam around circular cylinder
and compare with RASmodel and LESmodel
actually I have alreay tried creating the case created by LESmodel and observed vortex successfully.

but result of RASmodel is not good.
there is no vortex in RASmodel and I seems like laminar flow.
I don't know why vortex don't appear in RASmodel.

i think the problem is in k or epsilon.

please somebody help me.
it take for 2week to find what problem is.

my case file is attached.

https://docs.google.com/file/d/0B1jB...FGUnRpS1U/edit

wes1204 January 29, 2013 07:42

and
 
inlet velocity is 1m/s.
channel width is 4.5m
channel length is 17.5m
cylinder D=0.5m

k in 0 is 0.000375 by (3/2)*(U*I)^2 (I = 0.005)
epsilron in 0 is 0.0000026 by (Cu^0.75)(k^1.5 / l) (Cu=0.09 , I = 20% of channel width)
nu is 1e-06.

plese help me

wes1204 April 9, 2013 11:54

mesh problem.
 
Although this thread is written by me, I reply myself for other foamer who encounter to same problem.

Problem is Mesh.

I remake mesh more finer. Approximatly 2times.

Then vortex appeared.

Other condition is same.


All times are GMT -4. The time now is 05:42.