ENH: Added new noise utility to generate FFT metrics from pressure data

applications/utilities/postProcessing/noise/Make/files

+noise.C
+
+EXE = $(FOAM_APPBIN)/noise

applications/utilities/postProcessing/noise/Make/options

+EXE_INC = \
+    -I$(LIB_SRC)/randomProcesses/lnInclude \
+    -I$(LIB_SRC)/sampling/lnInclude
+
+EXE_LIBS = \
+    -lrandomProcesses \
+    -lsampling

applications/utilities/postProcessing/noise/createFields.H

+    word dictName("noiseDict");
+    if (args.optionFound("dict"))
+    {
+        dictName = args["dict"];
+    }
+
+    IOdictionary dict
+    (
+        IOobject
+        (
+            dictName,
+            runTime.system(),
+            runTime,
+            IOobject::MUST_READ
+        )
+    );
+
+    // reference pressure
+    scalar pRef = dict.lookupOrDefault("pRef", 0.0);
+
+    // number of samples in sampling window
+    label N = dict.lookupOrDefault("N", 65536);
+
+    // number of sampling windows
+    label nw = dict.lookupOrDefault("nw", 100);
+
+    // lower frequency of frequency band
+    scalar f1 = dict.lookupOrDefault("f1", 25.0);
+
+    // upper frequency of frequency band
+    scalar fU = dict.lookupOrDefault("fU", 10000.0);
+
+    // graph format
+    word graphFormat = dict.lookupOrDefault<word>("graphFormat", "raw");

applications/utilities/postProcessing/noise/noise.C

+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2011-2013 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/>.
+
+Application
+    noise
+
+Description
+    Utility to perform noise analysis of pressure data using the noiseFFT
+    library.
+
+    Control settings are read from the $FOAM_CASE/system/noiseDict dictionary,
+    or user-specified dictionary using the -dict option.  Pressure data is
+    read using a CSV reader:
+
+    \heading Usage
+
+    \verbatim
+    pRef        101325;
+    N           65536;
+    nw          100;
+    f1          25;
+    fU          10000;
+    graphFormat raw;
+
+    csvFileData
+    {
+        fileName        "pressureData"
+        nHeaderLine     1;
+        refColumn       0;
+        componentColumns (1);
+        separator       " ";
+    }
+    \endverbatim
+
+    where
+    \table
+        Property    | Description                   | Required  | Default value
+        pRef        | Reference pressure            | no        | 0
+        N           | Number of samples in sampling window | no | 65536
+        nw          | Number of sampling windows    | no        | 100
+        fl          | Lower frequency band          | no        | 25
+        fU          | Upper frequency band          | no        | 10000
+        graphFormat | Output grapch format          | no        | raw
+    \endtable
+
+
+SeeAlso
+    CSV.H
+
+\*---------------------------------------------------------------------------*/
+
+
+#include "noiseFFT.H"
+#include "argList.H"
+#include "Time.H"
+#include "functionObjectFile.H"
+#include "CSV.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+using namespace Foam;
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+Foam::scalar checkUniformTimeStep(const scalarField& t)
+{
+    // check that a uniform time step has been applied
+    scalar deltaT = -1.0;
+    if (t.size() > 1)
+    {
+        for (label i = 1; i < t.size(); i++)
+        {
+            scalar dT = t[i] - t[i-1];
+            if (deltaT < 0)
+            {
+                deltaT = dT;
+            }
+
+            if (mag(deltaT - dT) > SMALL)
+            {
+                FatalErrorIn("checkUniformTimeStep(const scalarField&)")
+                    << "Unable to process data with a variable time step"
+                    << exit(FatalError);
+            }
+        }
+    }
+    else
+    {
+        FatalErrorIn("checkUniformTimeStep(const scalarField&)")
+            << "Unable to create FFT with a single value"
+            << exit(FatalError);
+    }
+
+    return deltaT;
+}
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+int main(int argc, char *argv[])
+{
+    argList::noParallel();
+    #include "addDictOption.H"
+    #include "setRootCase.H"
+    #include "createTime.H"
+    #include "createFields.H"
+
+    Info<< "Reading data file" << endl;
+    CSV<scalar> pData("pressure", dict, "Data");
+
+    // time history data
+    const scalarField t(pData.x());
+
+    // pressure data
+    const scalarField p(pData.y());
+
+    if (t.size() < N)
+    {
+        FatalErrorIn(args.executable())
+            << "Block size N = " << N
+            << " is larger than number of data = " << t.size()
+            << exit(FatalError);
+    }
+
+    Info<< "    read " << t.size() << " values" << nl << endl;
+
+
+    Info<< "Creating noise FFT" << endl;
+    noiseFFT nfft(checkUniformTimeStep(t), p);
+
+    nfft -= pRef;
+
+    fileName baseFileName(pData.fName().lessExt());
+
+    graph Pf(nfft.RMSmeanPf(N, min(nfft.size()/N, nw)));
+    Info<< "    Creating graph for " << Pf.title() << endl;
+    Pf.write(baseFileName + graph::wordify(Pf.title()), graphFormat);
+
+    graph Lf(nfft.Lf(Pf));
+    Info<< "    Creating graph for " << Lf.title() << endl;
+    Lf.write(baseFileName + graph::wordify(Lf.title()), graphFormat);
+
+    graph Ldelta(nfft.Ldelta(Lf, f1, fU));
+    Info<< "    Creating graph for " << Ldelta.title() << endl;
+    Ldelta.write(baseFileName + graph::wordify(Ldelta.title()), graphFormat);
+
+    graph Pdelta(nfft.Pdelta(Pf, f1, fU));
+    Info<< "    Creating graph for " << Pdelta.title() << endl;
+    Pdelta.write(baseFileName + graph::wordify(Pdelta.title()), graphFormat);
+
+    Info<< nl << "End\n" << endl;
+
+    return 0;
+}
+
+
+// ************************************************************************* //