OpenFOAM-dev / data /src /waves /waveModels /irregular /waveSpectra /PiersonMoskowitz /PiersonMoskowitz.H
| /*---------------------------------------------------------------------------*\ | |
| ========= | | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | |
| \\ / O peration | Website: https://openfoam.org | |
| \\ / A nd | Copyright (C) 2023-2026 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. | |
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| 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::PiersonMoskowitz | |
| Description | |
| Pierson-Moskowitz wave spectrum. This spectrum has the following form: | |
| \f[ | |
| S(\omega) = \frac{\alpha g^2}{\omega^5} \exp \left(- \beta \\ | |
| \left( \frac{\omega_0}{\omega} \right)^4 \right) | |
| \f] | |
| \vartable | |
| \omega | angular frequency [rad/s], equal to \f$2 \pi f\f$ | |
| f | frequency [Hz] | |
| S(\omega) | spectral density [m^2/Hz] | |
| \alpha | coefficient, equal to 8.1e3 | |
| \beta | coefficient, equal to 0.74 | |
| \omega_0 | reference angular frequency, equal to \f$g/U_{19.5}\f$ | |
| U_{19.5} | reference velocity magnitude, 19.5 metres above the sea \\ | |
| surface | |
| \endvartable | |
| References: | |
| \verbatim | |
| Pierson Jr, W. J., & Moskowitz, L. (1964). | |
| A proposed spectral form for fully developed wind seas based on the \\ | |
| similarity theory of SA Kitaigorodskii. | |
| Journal of geophysical research, 69(24), 5181-5190. | |
| \endverbatim | |
| \verbatim | |
| Stewart, R. H. (2008). | |
| Introduction to physical oceanography. | |
| Robert H. Stewart. | |
| \endverbatim | |
| Usage | |
| \table | |
| Property | Description | Required? | Default | |
| U19_5 | The air speed 19.5 metres above the \\ | |
| surface [m/s] | yes | | |
| \endtable | |
| Example specification: | |
| \verbatim | |
| spectrum PiersonMoskowitz; | |
| PiersonMoskowitz | |
| { | |
| U19_5 15; | |
| } | |
| \endverbatim | |
| SourceFiles | |
| PiersonMoskowitz.C | |
| \*---------------------------------------------------------------------------*/ | |
| // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // | |
| namespace Foam | |
| { | |
| namespace waveSpectra | |
| { | |
| /*---------------------------------------------------------------------------*\ | |
| Class PiersonMoskowitz Declaration | |
| \*---------------------------------------------------------------------------*/ | |
| class PiersonMoskowitz | |
| : | |
| public waveSpectrum | |
| { | |
| // Private Data | |
| //- Reference velocity magnitude | |
| const scalar U19_5_; | |
| //- Alpha coefficient | |
| const scalar alpha_; | |
| //- Beta coefficient | |
| const scalar beta_; | |
| public: | |
| //- Runtime type information | |
| TypeName("PiersonMoskowitz"); | |
| // Constructors | |
| //- Construct a copy | |
| PiersonMoskowitz(const PiersonMoskowitz& spectrum); | |
| //- Construct from a dictionary and gravity | |
| PiersonMoskowitz(const dictionary& dict, const scalar g); | |
| //- Construct a clone | |
| virtual autoPtr<waveSpectrum> clone() const | |
| { | |
| return autoPtr<waveSpectrum>(new PiersonMoskowitz(*this)); | |
| } | |
| //- Destructor | |
| virtual ~PiersonMoskowitz(); | |
| // Member Functions | |
| //- Evaluate the wave spectral density at the given frequencies [m^2/Hz] | |
| virtual tmp<scalarField> S(const scalarField& f) const; | |
| //- Evaluate the integral of the wave spectral density at the given | |
| // frequencies [m^2] | |
| virtual tmp<scalarField> integralS(const scalarField& f) const; | |
| //- Return the frequency below which a given fraction of the spectrum's | |
| // total power falls [] | |
| virtual scalar fFraction(const scalar fraction) const; | |
| //- Write | |
| virtual void write(Ostream& os) const; | |
| }; | |
| // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // | |
| } // End namespace waveSpectra | |
| } // End namespace Foam | |
| // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // | |
| // ************************************************************************* // | |