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-   -   turbulentIntensityKineticEnergyInlet boundary condition (http://www.cfd-online.com/Forums/openfoam-pre-processing/108347-turbulentintensitykineticenergyinlet-boundary-condition.html)

sagnikmazumdar October 20, 2012 16:04

turbulentIntensityKineticEnergyInlet boundary condition
 
Dear all, I wonder what "value uniform 1; // placeholder" / "value uniform 200; // placeholder" mean in "turbulentIntensityKineticEnergyInlet" / "turbulentMixingLengthDissipationRateInlet" boundary condition !

The k and epsilon values can be solved from intensity and mixing length only. What does "value uniform" do ?

Thanks for the input.

Sagnik


PS: Boundary condition specifications:

inlet
{
type turbulentIntensityKineticEnergyInlet;
intensity 0.05; // 5% turbulence
value uniform 1; // placeholder
}

inlet
{
type turbulentMixingLengthDissipationRateInlet;
mixingLength 0.005; // 5 mm
value uniform 200; // placeholder
}

wyldckat October 20, 2012 16:35

Greetings Sagnik and welcome to the forum!

The need for the line with "value" is explained in the comment: it's merely a placeholder! In the sense that:
  1. The dictionary reading system requires that this line is present. You can try removing it and you'll see that the solver will complain about the missing entry.
  2. This "value" keyword is later used to store the fields that have been calculated in the next iterations!
Best regards,
Bruno

sagnikmazumdar October 21, 2012 13:22

Thanks a lot, Bruno .....

lllshahablll December 11, 2015 19:36

Dear Friends

I faced with following error using "turbulentIntensityKineticEnergyInlet" BC:


Code:

--> FOAM FATAL IO ERROR:
keyword value is undefined in dictionary "/home/shahabeddin/Desktop/elbow/0/k.boundaryField.velocity-inlet-6"

file: /home/shahabeddin/Desktop/elbow/0/k.boundaryField.velocity-inlet-6 from line 40 to line 42.

    From function dictionary::lookupEntry(const word&, bool, bool) const
    in file db/dictionary/dictionary.C at line 442.

FOAM exiting

and the definition is:
Code:

    velocity-inlet-6
    {
        type            turbulentIntensityKineticEnergyInlet;
        intensity      0.05        //5% turb inten
        value          uniform 0.0054;
    }

should I remove "value" keyword? or any other solution is exists?
I am using OpenFoam 3.0

nimasam December 12, 2015 03:03

you missed semicolone after intensity line

Quote:

intensity 0.05;


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