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How the boundary conditions are called in the OpenFOAM solvers? 

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February 1, 2014, 10:05 
How the boundary conditions are called in the OpenFOAM solvers?

#1 
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Dear All,
I was wondering how the boundary conditions subroutines are called ? Let us take an example: Code:
OpenFOAM/OpenFOAM2.1.1/tutorials/compressible/rhoPimpleFoam/les/pitzDaily Code:
U/0 Code:
inlet { type turbulentInlet; referenceField uniform (10 0 0); fluctuationScale (0.02 0.01 0.01); value uniform (10 0 0); } Thank you in advance! 

February 3, 2014, 01:54 

#2 
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Hrvoje Jasak
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Easy:
 on correctBoundaryConditions() for a field  on updateCoeffs() at matrix creation correctBoundaryConditions is also called after the linear solver call automatically. Enjoy, Hrv
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February 3, 2014, 12:16 

#3 
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Thank you so much, Hrvoje!
About the first one, I get it in the Code:
src/OpenFOAM/fields/GeometricFields/GeometricField/GeometricField.C Code:
// Correct the boundary conditions template<class Type, template<class> class PatchField, class GeoMesh> void Foam::GeometricField<Type, PatchField, GeoMesh>:: correctBoundaryConditions() { this>setUpToDate(); storeOldTimes(); boundaryField_.evaluate(); } Code:
src/OpenFOAM/fields/GeometricFields/GeometricField/GeometricField.H Code:
// Evaluate boundary conditions void evaluate(); 

February 3, 2014, 12:21 

#4 
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About the updateCoeffs in the turbulentInlet boundary conditions
Code:
OpenFOAM/OpenFOAM2.1.1/src/finiteVolume/fields/fvPatchFields/derived/turbulentInlet Code:
template<class Type> void turbulentInletFvPatchField<Type>::updateCoeffs() { if (this>updated()) { return; } if (curTimeIndex_ != this>db().time().timeIndex()) { Field<Type>& patchField = *this; Field<Type> randomField(this>size()); forAll(patchField, facei) { ranGen_.randomise(randomField[facei]); } // Correctionfactor to compensate for the loss of RMS fluctuation // due to the temporal correlation introduced by the alpha parameter. scalar rmsCorr = sqrt(12*(2*alpha_  sqr(alpha_)))/alpha_; patchField = (1  alpha_)*patchField + alpha_* ( referenceField_ + rmsCorr*cmptMultiply ( randomField  0.5*pTraits<Type>::one, fluctuationScale_ )*mag(referenceField_) ); curTimeIndex_ = this>db().time().timeIndex(); } fixedValueFvPatchField<Type>::updateCoeffs(); } Code:
fixedValueFvPatchField<Type>::updateCoeffs(); ++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++ As a record how I understand this, I put the answer here: evaluate() is defined in Code:
src/OpenFOAM/fields/GeometricFields/GeometricField/GeometricBoundaryField.C Code:
template<class Type, template<class> class PatchField, class GeoMesh> void Foam::GeometricField<Type, PatchField, GeoMesh>::GeometricBoundaryField:: evaluate() { if (debug) { Info<< "GeometricField<Type, PatchField, GeoMesh>::" "GeometricBoundaryField::" "evaluate()" << endl; } if ( Pstream::defaultCommsType == Pstream::blocking  Pstream::defaultCommsType == Pstream::nonBlocking ) { label nReq = Pstream::nRequests(); forAll(*this, patchi) { this>operator[](patchi).initEvaluate(Pstream::defaultCommsType); } // Block for any outstanding requests if ( Pstream::parRun() && Pstream::defaultCommsType == Pstream::nonBlocking ) { Pstream::waitRequests(nReq); } forAll(*this, patchi) { this>operator[](patchi).evaluate(Pstream::defaultCommsType); } } else if (Pstream::defaultCommsType == Pstream::scheduled) { const lduSchedule& patchSchedule = bmesh_.mesh().globalData().patchSchedule(); forAll(patchSchedule, patchEvali) { if (patchSchedule[patchEvali].init) { this>operator[](patchSchedule[patchEvali].patch) .initEvaluate(Pstream::scheduled); } else { this>operator[](patchSchedule[patchEvali].patch) .evaluate(Pstream::scheduled); } } } else { FatalErrorIn("GeometricBoundaryField::evaluate()") << "Unsuported communications type " << Pstream::commsTypeNames[Pstream::defaultCommsType] << exit(FatalError); } } 

February 5, 2014, 07:50 

#5 
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No Body also interested in this issue?


February 5, 2014, 10:27 

#6  
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As a newbie I asked a similar question in my latest post:
How can I make heat flux an external coupled BC like tempratur? Quote:
Code:
correctBoundaryConditions() { this>setUpToDate(); storeOldTimes(); boundaryField_.evaluate(); } Am I right? 

February 5, 2014, 18:33 

#7 
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Yes, I agree with you. I also did some digging into the source files. But do you know the role of the following lines:
Code:
fixedValueFvPatchField<Type>::updateCoeffs(); 

February 20, 2014, 16:46 

#8 
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I did not find this function in the source:
fixedValueFvPatchField.H Sorry for my limit C++ skills. Does anybody know where I can find this function, Code:
fixedValueFvPatchField<Type>::updateCoeffs(); 

February 20, 2014, 17:02 

#9 
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Hrvoje Jasak
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Please read up on virtual functions  this is basic C++
Hrv
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April 10, 2014, 06:30 

#10  
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For my record, actually, the following lines:
Code:
fixedValueFvPatchField<Type>::updateCoeffs(); The function updateCoeffs is defined in: Code:
fvPatchField.H Quote:


April 10, 2014, 06:32 

#11 
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Dear Dr Jasak,
The second item you mentioned: Code:
updateCoeffs() OFFO 

April 16, 2014, 17:54 

#12 
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my understanding so far is:
Those BC types that need updating and evaluation at each time step, they either have updateCoeffs() or evaluate() in the class definition, virtual of course. When a fvMatrix<type> Eqn is created, the updateCoeffs() is called in its constructor. Then in Eqn().solve() the function correctBoundaryConditions() is called, which contains evaluate(). Now the two functions are implemented differently in every BC, and the solver would also execute different things out according to each BC type defined. Thanks for corrections and improvement. peter 

December 19, 2014, 02:26 

#13 
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Abtin Ansari
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My understanding is that functions like updateCoeffs() and evaluate() are defined first in the upper code level virtually like in GeometricBoundaryField.C and overloaded(redefined) later in specific derived classes where actual math manipulation is done. For example lets look at fixedGradientFvPatchField.C in /src/finiteVolume/fields/fvPatchFields/basic/fixedGradient :
template<class Type> void fixedGradientFvPatchField<Type>::evaluate(const Pstream::commsTypes) { if (!this>updated()) { this>updateCoeffs(); } Field<Type>:perator= ( this>patchInternalField() + gradient_/this>patch().deltaCoeffs() ); fvPatchField<Type>::evaluate(); } Here , the value is updated based on specified gradient in BC file. Can somebody please verify since I'm I also new to C++? 

December 19, 2014, 13:38 

#14  
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I think what you said is correct.
Quote:


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