DES on 2D Domain

residual · May 6, 2021, 02:29

Hello,

I am trying to simulate transient variation of Drag and Lift Coefficient of cylinders for a range of Re ( 100 - 450).
I used URANS and Maximum value for Lift Coefficient i obtained was very different (Although mean value for Drag was acceptable).
anyway, Once i used DES, I could obtain very accurate results.

My question is whether it is acceptable to use DES in a 2D domain?.
I know a 3D domain would provide much more accurate results. But I need to simulate for a 2D Domain.

PenPencil · May 8, 2021, 21:29

Dear Upeka,

I have never used a 2D DES formulation, but I believe that Spalart & Allmaras (1992) - A One Equation Model for Aerodynamic Flows - calibrated the entire model based on 2D cases... and I think (not sure) the testing was also 2D.

However, you should not expect accurate results from any 2D formulation for cylinders in turbulent flow. Spanwise effects are very important there.

By the way, your range seems to contain both laminar and turbulent regimes, doesn't it? In the laminar I would not advise you to use DES; and in the turbulent regime the former consideration of 3D effects is of utmost importance.

May 6, 2021, 02:29	DES on 2D Domain	#1
residual New Member Upeka Join Date: Sep 2019 Location: Sri Lanka Posts: 8 Rep Power: 7	Hello, I am trying to simulate transient variation of Drag and Lift Coefficient of cylinders for a range of Re ( 100 - 450). I used URANS and Maximum value for Lift Coefficient i obtained was very different (Although mean value for Drag was acceptable). anyway, Once i used DES, I could obtain very accurate results. My question is whether it is acceptable to use DES in a 2D domain?. I know a 3D domain would provide much more accurate results. But I need to simulate for a 2D Domain.

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May 8, 2021, 21:29		#2
PenPencil New Member Icaro A. Carvalho Join Date: Dec 2020 Posts: 24 Rep Power: 5	Dear Upeka, I have never used a 2D DES formulation, but I believe that Spalart & Allmaras (1992) - A One Equation Model for Aerodynamic Flows - calibrated the entire model based on 2D cases... and I think (not sure) the testing was also 2D. However, you should not expect accurate results from any 2D formulation for cylinders in turbulent flow. Spanwise effects are very important there. By the way, your range seems to contain both laminar and turbulent regimes, doesn't it? In the laminar I would not advise you to use DES; and in the turbulent regime the former consideration of 3D effects is of utmost importance.