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time dependent BC with fully developed velocity profile

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Old   June 22, 2010, 14:13
Default time dependent BC with fully developed velocity profile
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Susheil Uthamaraj
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I am trying to simulate a pulsatile flow through a blood vessel. For doing this I created a profile file (*.prof) to generate a pulse required and applied this as a velocity-BC at the inlet. But this BC is a constant spatially.

For my purpose we would need a velocity pulse which is also fully developed. In other words, The how to apply a BC which varies both with respect to time and with respect to space.

Thanks.
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Old   June 22, 2010, 17:36
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Jouke de Baar
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What a nice problem.

You can do this quite easily using a user defined function (UDF). This means you will have to write a very short .c file and then compile it from FLUENT. After that you can use it as a boundary condition. It is quite possible to multiply a fully developed parabolic profile with a time dependent sine. Or whatever you want really.

Have a look at: http://www.hipecc.wichita.edu/pdfs/fludf.pdf
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Old   June 22, 2010, 17:44
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Jouke de Baar
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And then check the DEFINE_PROFILE for a velocity profile. If I remember correctly the function CURRENT_TIME should give the physical time you will need.

Good luck!
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Old   June 23, 2010, 10:43
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Susheil Uthamaraj
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Thanks,

The problem I am facing is that inlet in my model is not circular it is an irregular shape since this is blood vessel problem.
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Old   June 24, 2010, 08:44
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I'm afraid I can't help you there. Fluent can use an experimentally determined inflow profile, but I don't think this can be time dependent. There must be some smart way to do this, hopefully somebody else knows how?

Good luck!
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Old   June 24, 2010, 09:27
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Susheil Uthamaraj
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Thanks Jack. I will try to figure it out. Will post If i find out.
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Old   December 20, 2012, 06:41
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Marko Milasinovic
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Hi susheil,

I am working on a pulsatile flow through aorta. Have you solved how to input experimentally determined inflow profile which is time dependent?
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