PiersonMoskowitz.C

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License
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#include "PiersonMoskowitz.H"
#include "mathematicalConstants.H"
#include "addToRunTimeSelectionTable.H"
 
using namespace Foam::constant::mathematical;
 
// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
 
namespace Foam
{
namespace waveSpectra
{
    defineTypeNameAndDebug(PiersonMoskowitz, 0);
    addToRunTimeSelectionTable(waveSpectrum, PiersonMoskowitz, dictionary);
}
}
 
 
// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
Foam::waveSpectra::PiersonMoskowitz::PiersonMoskowitz
(
    const PiersonMoskowitz& spectrum
)
:
    waveSpectrum(spectrum),
    U19_5_(spectrum.U19_5_),
    alpha_(spectrum.alpha_),
    beta_(spectrum.beta_)
{}
 
 
Foam::waveSpectra::PiersonMoskowitz::PiersonMoskowitz
(
    const dictionary& dict,
    const scalar g
)
:
    waveSpectrum(dict, g),
    U19_5_(dict.lookup<scalar>("U19_5")),
    alpha_(dict.lookupOrDefault<scalar>("alpha", 8.1e-3)),
    beta_(dict.lookupOrDefault<scalar>("beta", 0.74))
{}
 
 
// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
 
Foam::waveSpectra::PiersonMoskowitz::~PiersonMoskowitz()
{}
 
 
// * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
 
Foam::tmp<Foam::scalarField> Foam::waveSpectra::PiersonMoskowitz::S
(
    const scalarField& f
) const
{
    const scalarField w(twoPi*f);
    const scalar w0 = g()/U19_5_;
    return twoPi*alpha_*sqr(g())/pow5(w)*exp(- beta_*pow4(w0/w));
}
 
 
Foam::tmp<Foam::scalarField> Foam::waveSpectra::PiersonMoskowitz::integralS
(
    const scalarField& f
) const
{
    const scalarField w(twoPi*f);
    const scalar w0 = g()/U19_5_;
    const scalar integralSInf = twoPi*alpha_*sqr(g())/(4*beta_*pow4(w0))/twoPi;
    return integralSInf*exp(- beta_*pow4(w0/w));
}
 
 
Foam::scalar Foam::waveSpectra::PiersonMoskowitz::fFraction
(
    const scalar fraction
) const
{
    const scalar w0 = g()/U19_5_;
    return w0/pow025(- log(fraction)/beta_)/twoPi;
}
 
 
void Foam::waveSpectra::PiersonMoskowitz::write(Ostream& os) const
{
    waveSpectrum::write(os);
 
    writeEntry(os, "U19_5", U19_5_);
    writeEntryIfDifferent<scalar>(os, "alpha", 8.1e-3, alpha_);
    writeEntryIfDifferent<scalar>(os, "beta", 0.74, beta_);
}
 
 
// ************************************************************************* //