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v2f model - periodic boundaries - turbulent viscosity limited to viscosity ratio

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Old   September 13, 2013, 11:05
Default k-omega SST vs V2-f
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Davide
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Hi all,

i'm trying to compare the performace of k-omega SST vs V2f. I'm simulating an hill.

this is the geometry of the simulation: link

profile at inlet should be such that the flow is in fully developed state. The paper provide me only the velocity profile.
To get the other profiles, i've setup a simulation of a flat terrain with periodic boundary conditions, as explained to me in this thread.

Residuals of the simulation with k-omega SST, for flat terrain (these are good): image
Residuals of the simulation with V2f, for flat terrain (these aren't good): image
As you can see the residuals tend to be periodic... After 350K iterations the periodic-pattern was still the same...

Using the profiles of k, omega,... obtained from simulations above, and the velocity profiles from the paper, i'll get these results: Result of hill simulations

I was expecting the k-omega SST to overstimate the recirculation region; this is the reason i have tryed the V2F. Anyway, i was also expecting the V2F to give better result in respect to k-omega SST; i was wrong...

What can i do to improve the result of V2F?

PS:
1 - all flat terrain simulations have: y+ < 1.
2 - y+ for hill simulations: image
3 - the Reynolds number should be < 4772.
Attached Images
File Type: jpg komegaSST-vs-V2f-y+.jpg (24.9 KB, 10 views)
File Type: jpg domain.jpg (99.0 KB, 13 views)
File Type: jpg residuals-v2f.jpg (67.4 KB, 9 views)
File Type: jpg residuals-k-omegaSST.jpg (59.7 KB, 8 views)

Last edited by Davide_sd; September 17, 2013 at 09:40. Reason: change the subject
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Old   September 14, 2013, 12:53
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Davide
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bump, i've changed the subject of the thread...
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