[Madeleine P. Vincent]

Hi all,

if I were interested in modeling vortex shedding behind a cylinder in incompressible flow, which Foam is best to use?

The Re will vary from 60 to 10,000.

Thanks,
Maddy.

[flowris]

You can start with icoFoam, the basic solver for incompressible flow. A more important question is the turbulence model you will use. There are numerous models, you can find more info on http://www.cfd-online.com/Wiki/Turbulence_modeling, but I suggest you also find a good textbook.

[vkrastev]

icoFoam for lower Reynolds number, pisoFoam or pimpleFoam for higher Reynolds number. However, have in mind that in this Reynolds number range (up to 10000) the flow exhibits a mixed laminar-turbulent behavior which is quite difficult to capture properly with standard RANS turbulence models. I have some experience at higher Reynolds numbers (from 1E05 to 3.6E06) and for such a flow regime some unsteady RANS models do a pretty good job in predicting vortex shedding frequencies and time-averaged drag values.

Regards

V.

[naveen]

hi all,

Use icoFoam for Re ranging from 0-300 and turbFoam or pimpleFoam for Re ranging from 300-20000 with SA Model or k-epsilon.


Regards

NAVEEN

[uli]

hi all

I am interested in vortex shedding at high Reynolds numbers (20.000 to 90.000). I found out that the solver turbfoam is no longer available in OF versions 1.6 and newer (I work with OF 1.7.x).

• Does anybody know why?
• can I import the turbfoam solver to OF 1.7.x?
• Which would be an appropriate alternative that allows me to add heat transfer / temperature (see http://openfoamwiki.net/index.php/Ho...ure_to_icoFoam )

I am new to openFOAM so any help and explanation is appreciated.

best
Uli

[flowris]

Both icoFoam and pimpleFoam can do simulations, and you can chose from a whole range of turbulence models in constant/turbulenceProperties.

[uli]

hi all,

since icoFoam is a solver for laminar flows I did simulations with pimpleFoam and pisoFoam, which produced similar results.

For any further suggestions see
http://www.cfd-online.com/Forums/mai...frequency.html
maybe we can continue the vortex shedding topic there.

Uli

[navidmt]

Hi, I am trying to simulate flow passing over an airfoil with a Reynolds number 60000 , I am modeling it using RANS with SA turbulence model. I am running it using pisoFoam solver and by checking the results, so far it's given good results but the problem is that it is very slow. I wanted to increase the speed of simulations and I read in one of the topics that using pimpleFoam since we can go for higher Courant number is an option. It gave the results very fast but when I check it , there was no vortex shedding and it looked like an average results.

Do you have any idea how I can set the pimpleFoam in order to capture vortex shedding?