Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case Implementing the pimpleFoam to oscillating flow solver porousOsciPimpleFoam using volume-averaged kOmega turbulence model Yanyan Zhai Applied Mechanics/Fluid Dynamics, Technical University of Denmark, Copenhagen, Denmark 2019-11-28 Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 1 / 30
Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case Outline Theory Background porosityZones Library solvers Turbulence model library Running the case Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 2 / 30
Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case Flow equation General flow equations Continuity equation ∂u i = 0 ∂x i Momentum equation ∂u i ∂t + ∂u i u j = − 1 ∂p ∂ ν ( ∂u i + ∂u j + ) + S i ∂x j ρ ∂x i ∂x j ∂x j ∂x i Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 3 / 30
Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case Flow equation Flow equations in porous media ∂ � u i � = 0 ∂x i ∂ � p � f (1 + C m ) ∂ � u i � + 1 ∂ � u i � � u i � = − 1 + g j ∂t n n ∂x j n ρ ∂x i + ∂ � u j � + 1 ∂ ν ( ∂ � u i � ) + F i + B i n ∂x j ∂x j ∂x i ρ 1 − n C m = γ p n � F i = aρ � u i � + bρ � u j � � u j � � u i � Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 4 / 30
Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case Turbulence model Standard kOmega model Turbulence Kinetic Energy ρ∂k ∂k ∂U i ∂ [( µ + σ ∗ µ T ) ∂k − β ∗ ρkω + ∂t + ρU j = τ ij ] ∂x j ∂x j ∂x j ∂x j Specific Dissipation Rate ρ∂ω ∂ω = αω ∂U i ∂ [( µ + σµ T ) ∂ω ∂t + ρU j k τ ij − βρω + ] ∂x j ∂x j ∂x j ∂x j Closure Coefficients β ∗ = 9 / 100 σ ∗ = 1 / 2 α = 5 / 9 β = 3 / 40 σ = 1 / 2 Auxiliary Relation 1 2 /ω ǫ = β ∗ ωk l = k Eddy Viscosity µ T = ρk/ω Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 5 / 30
Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case Turbulence model Volume-averaged kOmega model Turbulence Kinetic Energy � � u ′ i u ′ ∂ � k � + 1 ∂ � k � � u j � = ∂ [( ν + � ν t � σ ∗ ) ∂ � k � ∂ � u i � j ] − ∂t n ∂x j ∂x j ∂x j n ∂x j − β ∗ � ω � � k � + nβ ∗ ω ∞ k ∞ Specific Dissipation Rate � ∂ � u i � ∂ � ω � + 1 ∂ � ω � � u j � = ∂ [( ν + � ν t � σ ) ∂ � ω � ] − γ � ω � � u ′ i u ′ j ∂t n ∂x j ∂x j ∂x j n � k � ∂x j − β � ω � 2 + βω 2 ∞ k ∞ = 3 . 71 − n √ n ( � u 1 � 2 + � u 2 � 2 ) (1 − n ) 1 . 5 39 . 0 ( � u 1 � 2 + � u 2 � 2 ) 1 / 2 ω ∞ = 3 . 7 D 50 n 2 Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 6 / 30
Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case porosityZones Library The library is referred via a dictionary file named porosityZones in the tutorial as shown below. porousmedias { coordinateSystem { e1 (1 0 0); e2 (0 1 0); } resistanceFormulation vanGent1995; porosity 0.4; gammaAddedMass 0.34; d50 d50 [0 1 0 0 0 0 0] 0.036; alpha alpha [0 0 0 0 0 0 0] 500; beta beta [0 0 0 0 0 0 0] 2.0; } Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 7 / 30
Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case porosityZones Library Add the viscous and inertial resistance force contribution to the momentum equation void Foam::porosityZones::addResistance(fvVectorMatrix& UEqn) { forAll(*this, i) { operator[](i).addResistance(UEqn); } } Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 8 / 30
Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case porosityZones Library Porosity field will be written into 0 folder with the code in createPorosityFields.H porosityZones pZones(mesh); // Obtain the porosity field tmp<volScalarField> tporosity(pZones.porosity()); volScalarField& porosity = tporosity(); // Writes the porosity field to starting time folder porosity.write(); // Create a field with the porosity on the faces // Interpolated from the centers. surfaceScalarField porosityFace (fvc::interpolate(pZones.porosity()())); Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 9 / 30
Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case UEqn.H pimpleFoam Constructing the original momentum eqaution. tmp<fvVectorMatrix> UEqn ( fvm::ddt(U) + fvm::div(phi, U) + turbulence->divDevReff(U) == fvOptions(U) ); Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 10 / 30
Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case UEqn.H porousOsciPimpleFoam tmp<fvVectorMatrix> UEqn ( pZones.ddt(U) // + 1.0/pZones.porosity()*fvm::div(phi/(porosityFace), U) + turbulence->divDevReff(U) // Turbulence added == fvOptions(U) // Source term (not used) use via fvOptionsDict + bodyForcing->correct() // Source term due to body force ); The following code is added between ’UEqn().relax();’ and ’fvOptions.constrain(UEqn());’ pZones.addResistance(UEqn()); Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 11 / 30
Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case createFields.H porousOsciPimpleFoam The following code is added after U field volVectorField F ( IOobject ( "F", runTime.timeName(), mesh, IOobject::NO_READ, IOobject::AUTO_WRITE ),mesh, dimensionedVector("F", dimensionSet(0,1,-2,0,0,0,0), Foam::vector(0,0,0)) ); Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 12 / 30
Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case createFields.H porousOsciPimpleFoam Creating new dictionary in constant related to body force source term IOdictionary bodyForcingProperties ( IOobject ( "bodyForcingProperties", runTime.constant(), mesh, IOobject::MUST_READ, IOobject::NO_WRITE ) ); Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 13 / 30
Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case createFields.H porousOsciPimpleFoam Creating new sub-dictionary for bodyForcingProperties dictionary autoPtr<Foam::bodyForcing> bodyForcing ( Foam::bodyForcing::New ( mesh, mesh.lookupObject<IOdictionary> ("bodyForcingProperties").subDict("bodyForcing") ) ); Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 14 / 30
Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case bodyForcingProperties porousOsciPimpleFoam The dictionay in the case gives the basic information of oscillating flow bodyForcing { forceModel sinusoidalBodyForce; period 12; Um 2; constantSlope 0.000; forceDirection (1 0 0); } Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 15 / 30
Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case head file .C porousOsciPimpleFoam Two new files are added to use the class porosityZones and bodyforcing. #include "fvCFD.H" #include "singlePhaseTransportModel.H" #include "turbulenceModel.H" #include "pimpleControl.H" #include "fvIOoptionList.H" #include "IOporosityModelList.H" #include "IOMRFZoneList.H" #include "porosityZones.H" #include "bodyForcing.H" //BF Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 16 / 30
Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case main() in .C porousOsciPimpleFoam In this part, the following code is added after #include ”createMesh.H” to create the porosity field. #include "createPorosityFields.H" // porosity field The resistance induced by porous media is considered before ”runTime.write();”. F = pZones.porousBodyForce(U); // Calculating resistance from porosity Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 17 / 30
Outline Theory Background porosityZones Library Solvers Turbulence model library Runnning the case files in Make folder porousOsciPimpleFoam files in porousOsciPimpleFoam porousOsciPimpleFoam.C EXE = $(FOAM_USER_APPBIN)/porousOsciPimpleFoam files in pimpleFoam pimpleFoam.C EXE = $(FOAM_APPBIN)/pimpleFoam Yanyan Zhai porousOsciPimpleFoam with volume-averaged kOmega model 2019-11-28 18 / 30
Recommend
More recommend
