[cuikahlil]

Hello!

Is it possible in openfoam to implement some sort of on/off mechanism at the inlet? I am trying to simulate water entering a chamber through an inlet but would like the flow to start after a certain period of time.

Any ideas are welcome! Thank you in advance.

Kahlil

[RobertHB]

See if you can use any of the fvOptions entries. Those have a startTime and duration keyword.

[cuikahlil]

Oh dear how could I have forgotten that. I was thinking the solution would be a lot complicated. Thank you very much!

[cuikahlil]

I may have over estimated my familiarity with fvOptions. Would you be so kind to offer some suggestions which ones I can use? I have seen that acousticDampingSource has the time settings but I can't imagine using it for what I intend to do.

[RobertHB]

Originally Posted by cuikahlil

Would you be so kind to offer some suggestions which ones I can use?

The first option that comes to my mind is meanVelocityForce. You could defin your inlet as a cell set close the your inlet patch und use the meanVelocityForce to only drive the flow during a given time interval.

But i have never used the options with a time, and cant say for sure that it will work.


For further information about fvOptions entries you might want to look at this page: www.geocities.jp. Most of it is in japanese, but you can use google translate or the chrome browser to translate the website. The important parts are in english anyways.

[Bloerb]

    {
        type            uniformFixedValue;
        uniformValue    constant (1 0 0);
        value                uniform (0 0 0); // meaningless initial value
    }

or for a non constant velocity:

    {
        type            uniformFixedValue;
        uniformValue    table
        (
        (0.0 (1 0 0))
        (1.0 (1 0 0))
        (1.1 (0 0 0))
        );
    }

Keep in mind, that a linear interpolation is used between those.

[cuikahlil]

Thanks for the heads up Robert! I will definitely check this out.

[cuikahlil]

Hello Bloerb! which part in this code allows me to set the time when I want the inlet to release the water?

[RobertHB]

Originally Posted by cuikahlil

Hello Bloerb! which part in this code allows me to set the time when I want the inlet to release the water?

In short: none. You will have to add the timeStart and duration keywords. This at least worked in 2.2.x, see here. Couldt find those lines for 4.x or 5.x