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How to set up the velocity in the let boudary changing with time.

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Old   June 3, 2009, 10:23
Default How to set up the velocity in the let boudary changing with time.
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xinguang cui
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Hey Foamers:

I wish all of you have a nice day.
I need to simulate a case that the velocity in the inlet changes with the time.
How do I set up it ?
Is there existed solver or text that could be referenced by me?

Thanks and best wishes!
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Old   June 3, 2009, 10:57
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Leonardo Giampani Morita
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Hi,

I've not used it yet, but it seems that timeVaryingMappedFixedValue can be useful for you.

Regards,

Leonardo
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Old   June 3, 2009, 11:11
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Niels Gjoel Jacobsen
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And if the time variation can be specified by a mathematical expression you would benefit from groovyBC (just search the forum).

Best regards,

Niels
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Old   June 3, 2009, 11:25
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xinguang cui
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Thanks a lot to eonardo and Niels. I will try it.
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Old   June 4, 2009, 12:08
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xinguang cui
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Hey Leonardo:

I have read the thread, but it is very sad that I know few thing about "timeVaryingMappedFixedValue". Is it a utility?
How do I use it? And how could I generate the value for different time step?

Thanks and Best wishes!
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Old   June 4, 2009, 15:59
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Leonardo Giampani Morita
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Hello,

Well, I know it's not extensively documented, but you can search for more info here in the forum. Try the keywords: transient boundary conditions, timeVarying, nonuniform boundary conditions etc.

About your questions:

"Is it a utility?"
- it's a kind of boundary condition you can use with U, p etc (like fixedValue, zeroGradient...)

"How do I use it?"
- you can take a look into the simpleFoam/pitzDailyExptInlet tutorial for syntax and more

"And how could I generate the value for different time step?"
- as I don't know anything about your case and as I've never used it, it's a bit difficult to answer this one

Regards,

Leonardo
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Old   June 5, 2009, 08:50
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xinguang cui
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Thanks for your answer. I would like to know where I could see the source code for this boundary condition. I guess from the source code, I could get more information.

Best wishes!
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Old   June 5, 2009, 09:26
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Here: OpenFOAM-1.5\src\finiteVolume\fields\fvPatchFields\derived
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