Non-periodic wake, is it possible? (flow past a I-beam)
5 Attachment(s)
Hello,
I'm simulating a flow past a I-beam and, according to my solution, it has a periodic pattern in the beginning (periodic vortex shedding). But after sometime (aprox. 50 s) it seems to loose its periodicity. Please, see the attached figures. I would like to know if it's possible to have non-periodic wakes or it's just a simulation error? P.S.: I'm using a RANS turbulence model (k-omega SST) and I am using a unsteady solver. Thanks in advance. Attachment 57434 Attachment 57435 Attachment 57436 Attachment 57437 Attachment 57438 |
Well, you are actually trying a URANS formulation. From a physical point of view, when the flow becomes transitional towards the turbulence, there is no more reason to have a periodic vortex shedding (In DNS or LES you will see that). Now, the question is if the URANS can justify the presence of more oscillating frequency...
This is somehow more tricky, the unsteady solution could contain some low frequencies but their physical meaning is not so clear. |
Yep, that's exactly what I was wondering... My solution tells that the mean velocity does not have a periodic pattern. What would you say about it? Probably a simulation error or is it possible?
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I cannot say more, I never explored URANS for such problems... |
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