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August 6, 2019, 16:13
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Transition SST on laminar flow?
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#1 |
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New Member
Lukas
Join Date: Jul 2018
Posts: 20
Rep Power: 7  |
Hey Guys,
I am currently modelling a case where I suspect the flow to be laminar but I am not sure since it a complex geometry. Since applying a turbulence model when there is no turbulence to model has an (negative) impact on the results, I thought it should be safe to use the transition SST since its capable of modelling both, laminar and turbulent. Is this a wrong guess? Any hits, tricks or literature tips? Greetings Lukas |
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August 6, 2019, 20:07
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#2 |
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Senior Member
Svetlana Tkachenko
Join Date: Oct 2013
Location: Australia, Sydney
Posts: 407
Rep Power: 14 |
Did you do a mesh independence study?
How do you define "negative impact on the results"? |
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August 7, 2019, 04:12
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#3 |
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New Member
Lukas
Join Date: Jul 2018
Posts: 20
Rep Power: 7 |
I did an independency study using the sst model.
A negative impact would be generated turbulence where none should be or falsified transport of species. Another question: do i need any kind of Walltreatment in a laminar flow? Last edited by TU_Hiwi; August 7, 2019 at 05:23. |
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August 14, 2019, 11:01
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#4 |
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Member
MIDHUN
Join Date: Nov 2012
Location: calicut
Posts: 45
Rep Power: 13  |
can you specify the Re at different locations and give a screenshot of the geom
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August 14, 2019, 11:11
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#5 |
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New Member
Lukas
Join Date: Jul 2018
Posts: 20
Rep Power: 7 |
there will be really low Re, 1E-4 for a cylinder, so i am assuming its laminar.
I changed the inlet turbulence and the flow fields turbulence totaly depended on that inlet turbulence. In other words: there was nearly now generation of turbulence inside my model. Greetings |
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August 14, 2019, 11:42
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#6 |
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Member
MIDHUN
Join Date: Nov 2012
Location: calicut
Posts: 45
Rep Power: 13 |
why dont you solve with laminar model then ?
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August 14, 2019, 14:02
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#7 |
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New Member
Lukas
Join Date: Jul 2018
Posts: 20
Rep Power: 7 |
That is what i also thought after calculating the Re. But still, if i am using a turbulence model, inlet turbulence is zero, is it the same as modelling laminar?
Greetings |
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August 14, 2019, 14:06
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#8 |
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Member
MIDHUN
Join Date: Nov 2012
Location: calicut
Posts: 45
Rep Power: 13 |
use laminar and try .. what is the maximum diameter ? less than 1 mm?
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August 14, 2019, 14:11
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#9 |
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New Member
Lukas
Join Date: Jul 2018
Posts: 20
Rep Power: 7 |
the Diameter is 160E-6 m = 160 \mu m, v_in from 0,0075 m/s to 0,1 m/s
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August 14, 2019, 14:19
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#10 |
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Member
MIDHUN
Join Date: Nov 2012
Location: calicut
Posts: 45
Rep Power: 13 |
it will be laminar flow .. try laminar only .. if u need any furthe assitance contact me midhun6189@gmail.com
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