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Symulate hysteresis stall effect on an Airfoil

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Old   March 6, 2012, 06:34
Default Symulate hysteresis stall effect on an Airfoil
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Nicola
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Hi everyone!
My name is Nicola and i'm a doing some analysis in fluent for my thesis in Engeneering. I'm doing an analysis on effect of the stall hysteresis on an NACA0018 airfoil.
Some one can help me about how set the analysis?

I need to create a variation of the velocity direction in the velocity inlet surface.
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Old   March 6, 2012, 07:08
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I need to create a variation of the velocity direction in the velocity inlet surface.
Why? are you looking for post stall simulation?
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Old   March 6, 2012, 07:17
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Why? are you looking for post stall simulation?
Yes, i'm looking to simulate the post stall condition in particular the hysteresis phenomenon. If i want to simulate this, i need to decrease the angle of attach in the moment of deep stall and after increase it.... this to reproduce the hysteric phenomenon (see the attack file)
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Old   March 6, 2012, 07:35
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I need to decrease the angle of attack in the moment of deep stall and after increase it..
This should be done by computational model and not by you.
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Old   March 6, 2012, 07:38
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This should be done by computational model and not by you.
Yes, i agree your idea..... but HOW can i set the computational model to do this?
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Old   March 6, 2012, 07:44
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one idea which one of my student and my self implemented is to run the transient simulation at stall angle and it will give you required results. First it will go into stall and then it will try to recover. During recovering you get high angle of attack and high lift. After when it goes into stall, you get low lift and this loop repeats indefinitely.
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Old   March 6, 2012, 07:55
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Originally Posted by Far View Post
one idea which one of my student and my self implemented is to run the transient simulation at stall angle and it will give you required results. First it will go into stall and then it will try to recover. During recovering you get high angle of attack and high lift. After when it goes into stall, you get low lift and this loop repeats indefinitely.
Ok, i will try this afternoon!
I defined my model like in this tutorial:
https://confluence.cornell.edu/displ...oil+-+Geometry

So now i defined the angle of attack, like the different direction of wind in the velocity inlet surface. If i follow your method, i set the stall angle of attack (13 @ Re1,5e5) for the velocity inlet and i calculate a transient simulation. How much time must last the transient simulation?

Thank you very much for your help!
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