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January 26, 2015, 15:40 |
RASmodel laminar vs. simulationType laminar
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#1 |
Member
Thiago Parente Lima
Join Date: Sep 2011
Location: Diamantina, Brazil.
Posts: 62
Rep Power: 14 |
Hi,
I'm using the buoyantBoussinesqSimpleFoam in OF 2.3.1 to solve the classical vertically heated square enclosure with laminar flow (Ra=10^3 ). My first question is: What is the differennce between setting simulationType laminar in the turbulenceProperties dictionary and RASmodel laminar in RASProperties dictionary? Actually, I notice that the turbulenceProperties is not necessary when you set RASmodel laminar in RASProperties. However, the opposite is not true. Another question is: If the turbulence model is off, why do I still need to set all the turbulent properties in the /0 folder? Tkz. |
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January 27, 2015, 03:26 |
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#2 |
Senior Member
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Hi,
Here is how buoyantBoussinesqSimpleFoam creates turbulence model: Code:
... Info<< "Creating turbulence model\n" << endl; autoPtr<incompressible::RASModel> turbulence ( incompressible::RASModel::New(U, phi, laminarTransport) ); ... Code:
autoPtr<RASModel> RASModel::New ( const volVectorField& U, const surfaceScalarField& phi, transportModel& transport, const word& turbulenceModelName ) { // get model name, but do not register the dictionary // otherwise it is registered in the database twice const word modelType ( IOdictionary ( IOobject ( "RASProperties", U.time().constant(), U.db(), IOobject::MUST_READ_IF_MODIFIED, IOobject::NO_WRITE, false ) ).lookup("RASModel") ); Info<< "Selecting RAS turbulence model " << modelType << endl; dictionaryConstructorTable::iterator cstrIter = dictionaryConstructorTablePtr_->find(modelType); ... Code:
autoPtr<incompressible::turbulenceModel> turbulence ( incompressible::turbulenceModel::New(U, phi, laminarTransport) ); Code:
autoPtr<turbulenceModel> turbulenceModel::New ( const volVectorField& U, const surfaceScalarField& phi, transportModel& transport, const word& turbulenceModelName ) { // get model name, but do not register the dictionary // otherwise it is registered in the database twice const word modelType ( IOdictionary ( IOobject ( "turbulenceProperties", U.time().constant(), U.db(), IOobject::MUST_READ_IF_MODIFIED, IOobject::NO_WRITE, false ) ).lookup("simulationType") ); ... } |
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January 27, 2015, 11:28 |
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#3 |
Member
Thiago Parente Lima
Join Date: Sep 2011
Location: Diamantina, Brazil.
Posts: 62
Rep Power: 14 |
Ok, thank you for the answer.
I'm still in the superficial user level so... this is what I got: this is a carachteristic of the way the buoyantBoussinesqSimpleFoam creates the turbulence model (previously set as RASmodel (?)). In others applications, turbulencePropertires might be read first and then we need to set simulationType in turbulenceProperties. Once laminar was choosed, we shouldn't need any <tubulenceModel>Properties dictionary. Ok? |
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January 27, 2015, 11:38 |
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#4 |
Senior Member
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Yes, that is correct.
And answering your original question, there's no physical difference between "simulationType laminar" and "RASModel laminar". Both return zero volume fields for nut, k, epsilon, and omega. Difference is in the way classes are instantiated. |
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