/*---------------------------------------------------------------------------*\ ========= | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox \\ / O peration | Website: https://openfoam.org \\ / A nd | Copyright (C) 2024-2026 OpenFOAM Foundation \\/ M anipulation | ------------------------------------------------------------------------------- License This file is part of OpenFOAM. OpenFOAM is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. OpenFOAM is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenFOAM. If not, see . Class Foam::fv::wallBoiling Description Model for nucleate wall boiling between two phases on the surface of a number of wall patches. This model implements a version of the well-known RPI wall boiling model (Kurul & Podowski, 1991). The model is based on an implementation described in Peltola et al. (2019) and is similar to the model described by Peltola & Pättikangas (2012). References: \verbatim Kurul, N., & Podowski, M.Z. (1991). On the modeling of multidimensional effects in boiling channels. ANS. Proc. National Heat Transfer Con. Minneapolis, Minnesota, USA, 1991. ISBN: 0-89448-162-1, pp. 30-40. \endverbatim \verbatim Peltola, J., Pättikangas, T., Bainbridge, W., Lehnigk, R., Schlegel, F. (2019). On Development and validation of subcooled nucleate boiling models for OpenFOAM Foundation Release. NURETH-18 Conference Proceedings, Portland, Oregon, United States, 2019. \endverbatim \verbatim Peltola, J., & Pättikangas, T.J.H. (2012). Development and validation of a boiling model for OpenFOAM multiphase solver. CFD4NRS-4 Conference Proceedings, Daejeon, Korea, 2012. paper 59. \endverbatim Usage Example usage: \verbatim wallBoiling { type wallBoiling; libs ("libmultiphaseEulerFvModels.so"); // Note: Order is important. This model is one-way. It turns liquid // into vapour. The phases should be specified in this order. phases (water steam); energySemiImplicit no; saturationTemperature { type constant; value 372.76; } partitioningModel { type Lavieville; alphaCrit 0.2; } nucleationSiteModel { type LemmertChawla; Cn 1; NRef 30000000; deltaTRef 10; } departureDiameterModel { type TolubinskiKostanchuk; dRef 0.00024; dMax 0.0014; dMin 1e-06; } departureFrequencyModel { type KocamustafaogullariIshii; Cf 1.18; } } \endverbatim In addition to the above fvModel specification, wall patches on which boiling is to be calculated should have an alphatPhaseChangeWallFunction boundary condition applied to the turbulent thermal diffusivity field. See also Foam::alphatPhaseChangeWallFunctionFvPatchScalarField SourceFiles wallBoiling.C \*---------------------------------------------------------------------------*/ #ifndef wallBoiling_H #define wallBoiling_H #include "wallPhaseChange.H" #include "nucleation.H" #include "phaseSystem.H" // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // namespace Foam { // Forward declaration of classes namespace wallBoilingModels { class partitioningModel; class nucleationSiteModel; class departureDiameterModel; class departureFrequencyModel; } class wallBoilingPhaseChangeRateFvPatchScalarField; namespace fv { /*---------------------------------------------------------------------------*\ Class wallBoiling Declaration \*---------------------------------------------------------------------------*/ class wallBoiling : public wallPhaseChange, public nucleation { private: // Private classes //- Struct to hold properties that are held constant during the // iterative solution procedure struct laggedProperties; // Private Data //- Reference to the liquid phase const phaseModel& liquid_; //- Reference to the vapour phase const phaseModel& vapour_; //- Reference to the liquid turbulent thermal diffusivity const volScalarField& alphatLiquid_; //- Reference to the vapour turbulent thermal diffusivity const volScalarField& alphatVapour_; //- Reference to the field associated with the pressure equation const volScalarField& p_rgh_; //- Solution tolerance scalar tolerance_; //- Estimate liquid temperature using logarithmic wall function? bool liquidTemperatureWallFunction_; //- Turbulent Prandtl number scalar Prt_; //- Bubble waiting time ratio scalar bubbleWaitingTimeRatio_; //- Saturation temperature as a function of pressure autoPtr> Tsat_; //- Run-time selected heat flux partitioning model autoPtr partitioningModel_; //- Run-time selected nucleation site density model autoPtr nucleationSiteModel_; //- Run-time selected bubble departure diameter model autoPtr departureDiameterModel_; //- Run-time selected bubble departure frequency model autoPtr departureFrequencyModel_; //- Counter for the evaluations of the pressure equation sources mutable label pressureEquationIndex_; //- The phase change rate mutable volScalarField mDot_; // Private Member Functions //- Non-virtual read void readCoeffs(const dictionary& dict); //- Get the liquid temperature patch field and the parameters // associated with its boundary condition that are necessary for // approximately evaluating the boundary condition's heat flux at // a given wall temperature. const fvPatchScalarField& getLiquidTemperaturePatchField ( const laggedProperties& lagProps, scalarField& isFixed, scalarField& h, scalarField& hTaPlusQa ) const; //- Calculate the boiling for the given wall temperature. Return // the total sum of all heat fluxes. Set the properties passed by // non-const reference. Used by the functions below. tmp calcBoiling ( const laggedProperties& lagProps, const scalarField& TLiquid, const scalarField& wetFraction, scalarField& dDeparture, scalarField& fDeparture, scalarField& nucleationSiteDensity, scalarField& qQuenching, scalarField& qEvaporative, scalarField& mDot ) const; //- Calculate the boiling for the given wall temperature. Return // the total sum of all heat fluxes. Use this to solve the balance // between the heat fluxes specified by the boiling models and the // temperature boundary condition without changing the stored // boiling state. tmp calcBoiling ( const wallBoilingPhaseChangeRateFvPatchScalarField& mDot, const laggedProperties& lagProps, const scalarField& TLiquid ) const; //- Calculate the boiling for the given wall temperature. Return // the total sum of all heat fluxes. Also set the stored boiling // state. Use this after solving with the final wall temperature // to set the boiling state. tmp evaluateBoiling ( wallBoilingPhaseChangeRateFvPatchScalarField& mDot, const laggedProperties& lagProps, const scalarField& TLiquid ) const; //- Correct the phase change rate void correctMDot() const; public: //- Runtime type information TypeName("wallBoiling"); // Constructors //- Construct from explicit source name and mesh wallBoiling ( const word& name, const word& modelType, const fvMesh& mesh, const dictionary& dict ); // Member Functions // Access //- Return a mask indicating whether phase change is occurring virtual const scalarField& active(const label) const; //- Access the turbulent thermal diffusivities for a patch virtual Pair alphats(const label) const; // Evaluation //- Return the fraction of the latent heat that is transferred into // the second phase virtual tmp> Lfraction() const; //- Return the diameter of nuclei virtual tmp> d() const; //- Return the number rate at which nuclei are generated virtual tmp> nDot() const; //- Return the nucleation time scale virtual tmp> tau() const; // Sources //- Return the mass transfer rate virtual tmp> mDot() const; //- Return the mass transfer rate for the given patch const wallBoilingPhaseChangeRateFvPatchScalarField& mDotPf ( const label patchi ) const; //- Return the mass transfer rate for the given patch wallBoilingPhaseChangeRateFvPatchScalarField& mDotPfRef ( const label patchi ) const; //- Use phaseChange's source functions using phaseChange::addSup; //- Override the pressure equation to add the mass transfer rate // linearised in the pressure void addSup ( const volScalarField& alpha, const volScalarField& rho, fvMatrix& eqn ) const; //- Correct the fvModel virtual void correct(); // IO //- Read source dictionary virtual bool read(const dictionary& dict); }; // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // } // End namespace fv } // End namespace Foam // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // #endif // ************************************************************************* //