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

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!

Hi,

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

Regards,

Leonardo

And if the time variation can be specified by a mathematical expression you would benefit from groovyBC (just search the forum).

Best regards,

Niels

Thanks a lot to eonardo and Niels. I will try it.

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!

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

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!

Here: OpenFOAM-1.5\src\finiteVolume\fields\fvPatchFields\derived