[mecbe2002]

HI all,

Objective of my work is to replace the effusion holes with source and sink terms (mass, momentum and energy). For this I found out "codedSource" fvOptions is the best way.

I need help in calculating MFR at sink location and apply the same in source and sink locations.

massSourceEffusionHole
{
    type    scalarCodedSource;
    name    sourceTime;
    active  true;
    
    scalarCodedSourceCoeffs
    {            
        
        fields          (rho); 
        selectionMode   points;
        points //sink location
        (
            (0.035 0.034 0.0)
        );  
        codeInclude
        #{
        
        #};
        
        codeCorrect
        #{
        #};
        
        codeAddSup
        #{
            const Time& time1 = mesh().time();
            const volScalarField& rhoJet = mesh_.lookupObject<volScalarField>("rho");
            const volVectorField& velJet = mesh_.lookupObject<volVectorField>("U");
            scalarField& massSource1 = eqn.source();
            const labelList& cellIDs = cells();
        
            forAll(cellIDs, i)
            {
                label cellI = cellIDs[i];                
                massSource1[cellI] = rhoJet[cellI]*mag(velJet[cellI])*6.28319*1e-6;  
            }             
        #};
        
        codeSetValue
        #{
        #}
        
        // Dummy entry. Make dependent on above to trigger recompilation code
        #{
            $codeInclude
            $codeCorrect
            $codeAddSup
            $codeSetValue
        #};
    }
    
    sourceTimeCoeffs
    {
        $scalarCodedSourceCoeffs;    
    }
}

In the selection mode I have used "points" and specified the sink location, then calculating the MFR by getting the "rho" and "vel" at that location. I have applied the same in the sink location.

I need help in applying the MFR calculated at "sink" location to "source" location i.e. (0.0385 0.0365 0.0)


FYI
sink location (0.035 0.034 0.0)
source location (0.0385 0.0365 0.0)


Thanks
KGN

[superkelle]

http://www.cfd-online.com/Forums/ope...at-source.html
Does that maybe help? I dont know at which point exactly your problem is.

Is the problem to find the right cells at those locations? Then you can use some of the code I posted.

[mecbe2002]

Thanks for the reply. I actually referred your post.


Let me explain my problem in detail.
Objective of my work is to replace small diameter pipe (dia <0.5 mm) with source and sink terms i.e. inlet of the pipe will be sink and outlet of the pipe is source.
I have to use pressure drop across the pipe to calculate the mass flow rate; for this i need to get pressure at inlet and exit of the pipe.

• selection mode - points
• i have specified inlet and exit of the pipe location

In the below code, inside the "forAll" loop i can access only pressure values of current point in the loop. But i need to get pressure value at some other point for MFR calculation. How to do this?

 codeAddSup
#{            
     const volScalarField& rhoJet = mesh_.lookupObject<volScalarField>("rho");
     const volVectorField& velJet = mesh_.lookupObject<volVectorField>("v1");
     scalarField& massSource1 = eqn.source();
     const labelList& cellIDs = cells();
            
      forAll(cellIDs, i)
      {
          label cellSource = cellIDs[i];
           
          massSource1[cellSource] += rhoJet[cellSink]*mag(velJet[cellSink])*6.28319*1e-6;               
      }                          
#};

hope this explains my problem

[superkelle]

Maybe you better use two new boundary patches and there use custom coded bc since you do not have a wall at inlet and outlet of this channel.

[mecbe2002]

could you please elaborate your answer?