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shaswat November 11, 2011 07:06

profile boundary condition
1 Attachment(s)

I am doing blood flow simulation. I am going to use transient profile pressure as an inlet boundary condition.
I follow the steps as in the tutorial below

Pressure is my inlet boundary condition

I don't know how to setup pressure profile in the boundary details>mass and momentum>option>relative pressure.

Please help me

Thank you for your kind help


Attachment 9994

stumpy November 11, 2011 11:58

Has anybody validated that approach? I'm not convinced it's accurate since you would be using a distance weighted interpolation method to interpolate in time.

shaswat November 13, 2011 01:29

pressure profile_ urgent help needed
1 Attachment(s)
Dear all
please find the attached pressure with respect to time data
I would like to use this as an input . Kindly help me how to set up this in the inlet

Thank you


ghorrocks November 13, 2011 17:54

Use a 1D interpolation function and use the function for your boundary condition value.

shaswat November 14, 2011 02:25

1 Attachment(s)

Originally Posted by ghorrocks (Post 331890)
Use a 1D interpolation function and use the function for your boundary condition value.

Thank you Mr Glenn
Please find the attached document for your perusal.

Please comment on the following
1. Is my profile boundary correct?
2. I applied the following settings in the boundary details>mass and momentum>option>total pressure (stable)>Relative pressure>inlet.pressure(t)

Thank you



dotapro February 6, 2015 01:42

Dear Shaswat,
May I know how are you able to export spatial field [t] as I could only extract [x],[y],[z] ?


ghorrocks February 6, 2015 04:44

The file shown about was not exported but appears to be generated by hand.

Exporting the time variable is simply a matter of exporting the x,y,z field at each time step. This will get pretty tedious after a while so you will probably want a session file to automate it for you.

dotapro February 8, 2015 21:11

Yup, it become very tedious especially when you have a large bunch of time steps. So, can anyone gives me some ideas on how to write the session file and load it? I only manage to try on scripting and batch processing tutorial.

ghorrocks February 8, 2015 22:24

Start recording a session file, then do a few time steps and stop the session file. Load the session file up in a text editor and you should be able to figure out the syntax, it is not too complex. Then to generate a session file which will do the whole thing you can:
* copy/paste the text file and manually update things like the time step number
* write a python/matlab/whatever program which generates the test file and do a loop to generate the repetitive bit
* Use CFD-Post perl capabilities to do the looping directly.

I generally do the second option because I know python pretty well and I could not be bothered learning perl. But several people on this forum know perl pretty well so some would choose the perl option. If you don't want to code anything then do it the first way, it does not take that long to do unless you are talking about hundreds of time steps.

dotapro February 9, 2015 07:26

Dear Glen,

I will use the first method since I have no knowledge about coding. I have a question whereby I fail to initiate profile data if I manually program spatial field with x[m], y[m], z[m], t[s] as it can only accept three coordinates. Let say if i combine outlet.fixed mixture.temperature(x,y,t) + outlet.fixed mixture.temperature (z,t) in static temperature variables? Is it correct if I program it in such a way?

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