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Old   March 21, 2013, 06:48
Default Angle of attack not changed
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AndreiCFD
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Hi Foamers

I am simulating the flow over NACA23012 and it seems that when i change the angle of attack i am getting the same results. for example i changed from 0 deg to 5 deg using the Velocity*cos(angle) in x direction and Velocity*sin(angle) for y direction but the results seems to be the same even after i defined the angle of attack ..weird............. Might my inlet faces....what do you think?

Any suggestions......?

Thanks
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Old   March 21, 2013, 07:14
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What does your computational domain look like? What other boundary conditions do you have besides the velocity inlet?
A sketch or even a screenshot might be helpful.

And which soler are you using?
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Old   March 21, 2013, 07:33
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Quote:
Originally Posted by flotus1 View Post
What does your computational domain look like? What other boundary conditions do you have besides the velocity inlet?
A sketch or even a screenshot might be helpful.

And which soler are you using?
Thanks for reply

below i attached my sketch and sorry for the poor quality but you can understand ... I am using k omega sst and simpleFoam. solver
the wall represents my domain ... The inlet is defined 10 meters away from the wall and the outlet is defined 15 m away from the trailing edge.......

Thanks again
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File Type: jpg domain.jpg (75.2 KB, 15 views)
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Old   March 21, 2013, 08:41
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And the chord length is? I mean, if the chord is 1m in length I believe the boundaries are too close. They should be at approximately 20c away.
Something else, I don't know how openfoam works, but you should check whether it uses angles in degrees or in rads.
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Old   March 21, 2013, 09:04
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Just like I thought...

The straight boundaries (symmetry I guess) at the top and bottom of your domain guide the flow towards an AoA of 0. No matter what you specify at the inlet.
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Old   March 24, 2013, 10:50
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Yes for AOA study you should modify domain to circular at inlet and boundaries should be placed at 15-20 C at inlet and 25-30 C at outlet.
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