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susheil June 22, 2010 14:13

time dependent BC with fully developed velocity profile
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.


jack1980 June 22, 2010 17:36

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:

jack1980 June 22, 2010 17:44

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!

susheil June 23, 2010 10:43


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.

jack1980 June 24, 2010 08:44

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!

susheil June 24, 2010 09:27

Thanks Jack. I will try to figure it out. Will post If i find out.

milasko December 20, 2012 06:41

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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