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Weird behavior of TKE(K) using kOmegaSST for my case

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Old   April 6, 2023, 16:32
Default Weird behavior of TKE(K) using kOmegaSST for my case
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Farzad Faraji
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Hello all
I am using motorbike example to simulate my airfoil like geometry. After simulation velocity field and pressure fields are ok, but TKE(k) field shows weird behavior. it must show higher k in the downstream, but it shows zero k(TKE) in the downstream and in other places it shows higher k(TKE) where in those location k(TKE) must be zero.
Also, I have attached larger image for k(TKE) and Oemga filed and it seems that Omega has a singularity point, but mesh and simulation works fine.

I will be thankful for any suggestion.



Thanks,
Farzad
Attached Images
File Type: jpg motorbike.jpg (27.0 KB, 6 views)
File Type: jpg airfoil like shape.jpg (75.4 KB, 6 views)
File Type: jpg k-omega.jpg (60.9 KB, 3 views)
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Old   April 6, 2023, 18:13
Default just added limitedlinear 1
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Farzad Faraji
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The only real difference between my simulation and motorbike is that I have modified fvSchemes a little bit using lomitedlinear 1, where 1 is the coefficient. I have attached the divSchemes to this post.


Thanks
Farzad
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File Type: jpg fvSchemes.jpg (58.9 KB, 1 views)

Last edited by farzadmech; April 6, 2023 at 20:51.
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Old   April 6, 2023, 20:59
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Farzad Faraji
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ok, I find what was my problem, recalculate k and omega based 2% turbulence intensity and 10% of the Lref(length of my shape) as my turbulent length scale;
Code:
Turbulent intensity = 2%*UfreeStream
Turbulent length scale = 10%*GeometryLength
And now my results are good. I have attached my new results to this post.


Thanks,
Farzad

Quote:
Originally Posted by farzadmech View Post
Hello all
I am using motorbike example to simulate my airfoil like geometry. After simulation velocity field and pressure fields are ok, but TKE(k) field shows weird behavior. it must show higher k in the downstream, but it shows zero k(TKE) in the downstream and in other places it shows higher k(TKE) where in those location k(TKE) must be zero.
Also, I have attached larger image for k(TKE) and Oemga filed and it seems that Omega has a singularity point, but mesh and simulation works fine.

I will be thankful for any suggestion.



Thanks,
Farzad
Attached Images
File Type: jpg kOmegaRecalculation.jpg (78.5 KB, 5 views)
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