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How to set up U on outlet?

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Old   May 2, 2011, 02:19
Default How to set up U on outlet?
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Hi there,

How do I set up velocity at the outlet if I don't know the value?
I tried with zeroGradient and calculated. In both ways the solver crashes.

How do you set up?

How do one set up outletInlet? outletValue, value are needed. Are these values only a guess? I don't think so. Thus I can't use them because I don't know the value of velocity at the outlet.

When I run with simpleFoam the use of zeroGradient is very good. But when I want to use zeroGradient for chtMultiRegionSimpleFoam there appears an error.

Best Regards,
tH3f0rC3

Last edited by tH3f0rC3; May 2, 2011 at 02:45.
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Old   May 2, 2011, 02:45
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Bernhard
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You need to be more specific about your case. What is the physics at your outlet?
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Old   May 2, 2011, 04:05
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I have modeled a turbulent flow.
I know the inlet conditions very well. So I can set up the inlet boundary conditions with fixed Values.
On the outlet there is ambient pressure.

The model I created is a big room where hot air is circulated around. The air is blown in on many inlets (little pipes). There is one other inlet (Brennerinlet) which can be disregarded or set to fixedValue zero.

The outlet is on the top of the cuboid building.
Do you need any further information?

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tH3f0rC3
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Old   May 2, 2011, 05:51
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Samuel ARNAUD
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Set:
Code:
outlet
    {
        type            inletOutlet;
        inletValue      uniform (0 0 0);
        value           $internalField;
    }
that worked for all my cases.

I don't get the other outlet: why does it exist if you consider it's "closed"?
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Old   May 2, 2011, 08:06
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Ok thank you.
The other outlet is an outlet which I will delete for the next version of my case. But in the version I have uploaded the outlet is still set up as an existing outlet.

Many thanks,
I will try tomorrow.

Best Regards,
tH3f0rC3

Last edited by tH3f0rC3; May 2, 2011 at 12:28.
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