ENH: Added new structure for run-time selectable noiseModels

src/randomProcesses/noise/noiseModels/noiseModel/noiseModel.C

@@ -0,0 +1,150 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2015 OpenCFD Ltd.
+     \\/     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/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "noiseModel.H"
+
+// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
+
+namespace Foam
+{
+    defineTypeNameAndDebug(noiseModel, 0);
+    defineRunTimeSelectionTable(noiseModel, dictionary);
+}
+
+// * * * * * * * * * * * * * Protected Member Functions  * * * * * * * * * * //
+
+Foam::scalar Foam::noiseModel::checkUniformTimeStep
+(
+    const scalarList& times
+) const
+{
+    scalar deltaT = -1.0;
+
+    if (times.size() > 1)
+    {
+        for (label i = 1; i < times.size(); i++)
+        {
+            scalar dT = times[i] - times[i-1];
+
+            if (deltaT < 0)
+            {
+                deltaT = dT;
+            }
+
+            if (mag(deltaT - dT) > SMALL)
+            {
+                FatalErrorInFunction
+                    << "Unable to process data with a variable time step"
+                    << exit(FatalError);
+            }
+        }
+    }
+    else
+    {
+        FatalErrorInFunction
+            << "Unable to create FFT with a single value"
+            << exit(FatalError);
+    }
+
+    return deltaT;
+}
+
+
+Foam::label Foam::noiseModel::findStartTimeIndex
+(
+    const instantList& allTimes,
+    const scalar startTime
+) const
+{
+    forAll(allTimes, timeI)
+    {
+        const instant& i = allTimes[timeI];
+
+        if (i.value() >= startTime)
+        {
+            return timeI;
+        }
+    }
+
+    return 0;
+}
+
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+Foam::noiseModel::noiseModel(const dictionary& dict)
+:
+    dict_(dict),
+    pRef_(dict.lookupOrDefault("pRef", 0)),
+    nSamples_(dict.lookupOrDefault("N", 65536)),
+    fLower_(dict.lookupOrDefault("fl", 25)),
+    fUpper_(dict.lookupOrDefault("fu", 10000)),
+    startTime_(dict.lookupOrDefault("startTime", 0)),
+    windowModelPtr_(windowModel::New(dict, nSamples_))
+{
+    // Check number of samples  - must be a power of 2 for our FFT
+    bool powerOf2 = ((nSamples_ != 0) && !(nSamples_ & (nSamples_ - 1)));
+    if (!powerOf2)
+    {
+        FatalIOErrorInFunction(dict)
+            << "N: Number of samples in sampling windows must be a "
+            << "power of 2"
+            << exit(FatalIOError);
+    }
+
+    if (fLower_ < 0)
+    {
+        FatalIOErrorInFunction(dict)
+            << "fl: lower frequency bound must be greater than zero"
+            << exit(FatalIOError);
+
+    }
+
+    if (fUpper_ < 0)
+    {
+        FatalIOErrorInFunction(dict)
+            << "fu: upper frequency bound must be greater than zero"
+            << exit(FatalIOError);
+
+    }
+
+    if (fUpper_ < fLower_)
+    {
+        FatalIOErrorInFunction(dict)
+            << "fu: upper frequency bound must be greater than lower "
+            << "frequency bound (fl)"
+            << exit(FatalIOError);
+
+    }
+}
+
+
+// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
+
+Foam::noiseModel::~noiseModel()
+{}
+
+
+// ************************************************************************* //