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C-grid and angle-of-attack for airfoil

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Old   August 2, 2012, 18:17
Default C-grid and angle-of-attack for airfoil
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Clifton Perkins
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I want to simulate different angles-of-attack (AOA) for flow over the NACA 0012 airfoil. I'm using the NASA C-grids, from:

http://turbmodels.larc.nasa.gov/naca0012_grids.html

Re-meshing isn't an option and I'm not sure to handle the different AOA. There are results at the NASA website for different AOA, so I'm assuming there's a standard approach for dealing with this issue.

I know that the obvious thing to do is just change the inlet BC to match the AOA. But with this I run into a couple of issues for non-0 AOA:

- the flow is no longer parallel to the side (virtual) walls of the domain; I am using free-slip BC there, to help with convergence, but could try free inflow/outflow (aka Riemann BC I think) instead

- at one end of my inlet (inlet = C-shaped portion of boundary), I get "inflow" BCs that are actually pointing out of the domain (I guess I could modify the location at which "inlet" becomes "side" to avoid this, but would then need different region labeling for each AOA)

Does anyone have a recommendation on how to proceed?

I'm using a commercial CFD package, but probably better not say which one.

Thanks for all replies!!
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Old   August 3, 2012, 04:09
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Hey Clifton,
just to clarify: are you doing sub or supersonic flows?
cheers
cfd newbie
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Old   August 3, 2012, 10:26
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Clifton Perkins
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Thanks for your reply, cfd newbie. I'm sorry, I should have mentioned that it's incompressible flow and yes, subsonic.
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Old   August 14, 2012, 03:23
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Haris Hameed
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hi

why dont you use pressure farfield boundary condition...

i have simulated the same 2D cases in fluent (commercial pakage) got good results even for aoa 10 deg and 15 deg

i dont know ur solver so cant comment on ur strategy
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angle of attack, boundary conditions, c-grid, naca 0012

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