| /*---------------------------------------------------------------------------*\ | |
| ========= | | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | |
| \\ / O peration | Website: https://openfoam.org | |
| \\ / A nd | Copyright (C) 2011-2026 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 <http://www.gnu.org/licenses/>. | |
| Class | |
| Foam::reactionModels::FSD | |
| Description | |
| Flame Surface Density (FDS) reaction model. | |
| The fuel source term is given by mgft*pc*omegaFuelBar. | |
| where: | |
| mgft: filtered flame area. | |
| pc: probability of the reaction progress. | |
| omegaFuelBar: filtered consumption speed per unit of flame area. | |
| pc is considered from the IFC solution. | |
| omegaFuelBar is calculated solving a relaxation equation which tends to | |
| omegaEq. This omegaEq is obtained from the flamelet solution for | |
| different strain rates and fit using a exponential distribution. | |
| The spatial distribution of the consumption speed (omega) is obtained also | |
| from a strained flamelet solution and it is assumed to have a gaussian | |
| distribution. | |
| If the grid resolution is not enough to resolve the flame, the consumption | |
| speed distribution is linearly thickened conserving the overall heat | |
| release. | |
| If the turbulent fluctuation of the mixture fraction at the sub-grid level | |
| is large (>1e-04) then a beta pdf is used for filtering. | |
| At the moment the flame area reaction model is only fit to work in a LES | |
| frame work. In RAS the subgrid fluctuation has to be solved by an extra | |
| transport equation. | |
| SourceFiles | |
| FSD.C | |
| \*---------------------------------------------------------------------------*/ | |
| // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // | |
| namespace Foam | |
| { | |
| namespace reactionModels | |
| { | |
| /*---------------------------------------------------------------------------*\ | |
| Class FSD Declaration | |
| \*---------------------------------------------------------------------------*/ | |
| class FSD | |
| : | |
| public singleStepReaction | |
| { | |
| // Private Data | |
| //- Auto pointer to consumption speed per unit of flame area model | |
| autoPtr<reactionRateFlameArea> reactionRateFlameArea_; | |
| //- Mixture fraction | |
| volScalarField ft_; | |
| //- Fuel mass concentration on the fuel stream | |
| dimensionedScalar YFuelFuelStream_; | |
| //- Oxygen mass concentration on the oxidiser stream | |
| dimensionedScalar YO2OxiStream_; | |
| //- Similarity constant for the sub-grid ft fluctuations | |
| scalar Cv_; | |
| //- Model constant | |
| scalar C_; | |
| //- Lower flammability limit | |
| scalar ftMin_; | |
| //- Upper flammability limit | |
| scalar ftMax_; | |
| //- Dimension of the ft space. Used to integrate the beta-pdf | |
| scalar ftDim_; | |
| //- Minimum mixture fraction variance to calculate pdf | |
| scalar ftVarMin_; | |
| // Private Member Functions | |
| //- Calculate the normalised fuel source term | |
| void calculateSourceNorm(); | |
| public: | |
| //- Runtime type information | |
| TypeName("FSD"); | |
| // Constructors | |
| //- Construct from components | |
| FSD | |
| ( | |
| const word& modelType, | |
| const fluidMulticomponentThermo& thermo, | |
| const compressibleMomentumTransportModel& turb, | |
| const word& reactionProperties | |
| ); | |
| //- Disallow default bitwise copy construction | |
| FSD(const FSD&) = delete; | |
| //- Destructor | |
| virtual ~FSD(); | |
| // Member Functions | |
| //- Correct reaction rate | |
| virtual void correct(); | |
| //- Update properties | |
| virtual bool read(); | |
| // Member Operators | |
| //- Disallow default bitwise assignment | |
| void operator=(const FSD&) = delete; | |
| }; | |
| // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // | |
| } // End namespace reactionModels | |
| } // End namespace Foam | |
| // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // | |
| // ************************************************************************* // | |