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Old   November 7, 2013, 16:15
Default Time-accurate simulation
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Mandar Kulkarni
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Hello SU2 developers,

1.
The AIAA-2013-0287 Aerospace Sciences Meeting paper mentions the following test case:

Pitching NACA 64A010 airfoil

However this is not included in the test cases provided on the SU2 website. Is it possible for you to provide this test case?

2.
I am trying to an unsteady analysis where I have to provide a different angle of attack at each time step. This would be equivalent to rigidly pitching the airfoil, but now instead of a specific angular velocity, there will be a time dependent rotational motion of the airfoil. Is it possible to supply a function such as

A0A = some function of time

and do an unsteady analysis?

Thanks,
Mandar
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Old   November 19, 2013, 18:02
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Thomas D. Economon
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Hi Mandar,

Great to hear that you're interested in unsteady flows on dynamic meshes! We are working on a bunch of interesting features related to these types of problems, including adjoint-based aerodynamic design.

Quote:
Originally Posted by kmandar View Post

1.
The AIAA-2013-0287 Aerospace Sciences Meeting paper mentions the following test case:

Pitching NACA 64A010 airfoil

However this is not included in the test cases provided on the SU2 website. Is it possible for you to provide this test case?
No problem - I am attaching a config file for this case here. Do you have access to a mesh for this airfoil?

Quote:
Originally Posted by kmandar View Post
2.
I am trying to an unsteady analysis where I have to provide a different angle of attack at each time step. This would be equivalent to rigidly pitching the airfoil, but now instead of a specific angular velocity, there will be a time dependent rotational motion of the airfoil. Is it possible to supply a function such as

A0A = some function of time

and do an unsteady analysis?
In the attached config file, we are performing a rigid transformation of the mesh to simulate the pitching airfoil where the angle of attack is being prescribed as:

alpha(t) = amplitude * sin( omega * t )

Note that you can also include a phase offset. Please see the routine CVolumetricMovement::Rigid_Pitching(CGeometry *geometry, CConfig *config, unsigned short iZone, unsigned long iter) in the file grid_movement_structure.cpp for more details.

Hope this helps,
Tom
Attached Files
File Type: zip pitching_NACA64A010.cfg.zip (4.9 KB, 21 views)
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Old   November 19, 2013, 18:24
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Mandar Kulkarni
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Hi Tom,

Thanks for the configuration file. This definitely helps. Yes, I got the mesh for NACA 64A010 from the test case files for version 2.0.8.

I have recently started to go through the .cpp files. I will post here if I get hung up on something.

Best regards,
Mandar
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Old   February 16, 2015, 20:43
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Kan
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Quote:
Originally Posted by economon View Post
Hi Mandar,

Great to hear that you're interested in unsteady flows on dynamic meshes! We are working on a bunch of interesting features related to these types of problems, including adjoint-based aerodynamic design.



No problem - I am attaching a config file for this case here. Do you have access to a mesh for this airfoil?



In the attached config file, we are performing a rigid transformation of the mesh to simulate the pitching airfoil where the angle of attack is being prescribed as:

alpha(t) = amplitude * sin( omega * t )

Note that you can also include a phase offset. Please see the routine CVolumetricMovement::Rigid_Pitching(CGeometry *geometry, CConfig *config, unsigned short iZone, unsigned long iter) in the file grid_movement_structure.cpp for more details.

Hope this helps,
Tom
Hello Tom,

I've checked the config file from https://github.com/su2code/TestCases...NACA64A010.cfg for rans simulation, and also the AGARD's report. However, I found some values from config file are not consistent with experiment condition. For example, the pitching angular freq (rad/s) from config file is 106.69842, but the frequency from the AGARD report is 34.4, which then results in the angular freq of 216.14157088.

I suspect it could be the reason that the inflow pressure and temperature is not given, so to meet the reduced frequency of 0.202, this angular freq was used in the config file, is it?

Also, I am lost which mean angle of attack should I use, in your AAIAA-2013-0287 Aerospace Sciences Meeting paper, a mean angle of attack of 0 was used, but in the AGARD report, Table 2.1 and 2.4 said that this mean AoA is -0.21, while 0 in talble 2.2. Is there using the different mean AoA?

Thank you,
Kan
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