From 769dcffe0b4daedef7ddce9b89c7df1f826785fa Mon Sep 17 00:00:00 2001
From: Mark Olesen <Mark.Olesen@esi-group.com>
Date: Tue, 17 Oct 2023 15:00:36 +0200
Subject: [PATCH] ENH: support user-defined sampleFreq for noise models (#2999)
CONFIG: downgrade non-uniform time from error to warning
- can be a spurious error when the deltaT is very small
CONFIG: support keywords 'minFreq', 'maxFreq'
- these are the updated naming for 'fl' and 'fu' (still supported)
---
.../noise/noiseModels/noiseModel/noiseModel.C | 62 +++++++++++++------
.../noise/noiseModels/noiseModel/noiseModel.H | 17 +++--
.../noise/noiseModels/pointNoise/pointNoise.C | 7 ++-
.../noiseModels/surfaceNoise/surfaceNoise.C | 18 ++++--
4 files changed, 72 insertions(+), 32 deletions(-)
diff --git a/src/randomProcesses/noise/noiseModels/noiseModel/noiseModel.C b/src/randomProcesses/noise/noiseModels/noiseModel/noiseModel.C
index f72297c6e52..73cca53db73 100644
--- a/src/randomProcesses/noise/noiseModels/noiseModel/noiseModel.C
+++ b/src/randomProcesses/noise/noiseModels/noiseModel/noiseModel.C
@@ -5,7 +5,7 @@
\\ / A nd | www.openfoam.com
\\/ M anipulation |
-------------------------------------------------------------------------------
- Copyright (C) 2015-2022 OpenCFD Ltd.
+ Copyright (C) 2015-2023 OpenCFD Ltd.
-------------------------------------------------------------------------------
License
This file is part of OpenFOAM.
@@ -185,29 +185,34 @@ Foam::scalar Foam::noiseModel::checkUniformTimeStep
const scalarList& times
) const
{
- scalar deltaT = -1.0;
+ scalar deltaT = 1;
if (times.size() > 1)
{
// Uniform time step
- deltaT = (times.last() - times.first())/scalar(times.size() - 1);
+ deltaT = (times.back() - times.front())/scalar(times.size() - 1);
- for (label i = 1; i < times.size(); ++i)
+ bool nonUniform = false;
+ for (label i = 1; i < times.size() && !nonUniform; ++i)
{
- scalar dT = times[i] - times[i-1];
+ const scalar dT = times[i] - times[i-1];
- if (mag(dT/deltaT - 1) > 1e-8)
- {
- FatalErrorInFunction
- << "Unable to process data with a variable time step"
- << exit(FatalError);
- }
+ nonUniform = (mag(dT/deltaT - 1) > 1e-8);
+ }
+
+ if (nonUniform)
+ {
+ WarningInFunction
+ << "Detected non-uniform time step:"
+ << " resulting FFT may be incorrect"
+ << " (or the deltaT is just very small): " << deltaT
+ << endl;
}
}
else
{
FatalErrorInFunction
- << "Unable to create FFT with a single value"
+ << "Unable to create FFT with 0 or 1 values"
<< exit(FatalError);
}
@@ -617,6 +622,7 @@ Foam::noiseModel::noiseModel
nSamples_(65536),
fLower_(25),
fUpper_(10000),
+ sampleFreq_(0),
startTime_(0),
windowModelPtr_(),
SPLweighting_(weightingType::none),
@@ -654,10 +660,16 @@ bool Foam::noiseModel::read(const dictionary& dict)
return false;
}
+ // Re-assign defaults (to avoid stickiness)
+ fLower_ = 25;
+ fUpper_ = 10000;
+ sampleFreq_ = 0;
+
dict.readIfPresent("rhoRef", rhoRef_);
dict.readIfPresent("N", nSamples_);
- dict.readIfPresent("fl", fLower_);
- dict.readIfPresent("fu", fUpper_);
+ dict.readIfPresentCompat("minFreq", {{"fl", 2312}}, fLower_);
+ dict.readIfPresentCompat("maxFreq", {{"fu", 2312}}, fUpper_);
+ dict.readIfPresent("sampleFreq", sampleFreq_);
dict.readIfPresent("startTime", startTime_);
dict.readIfPresent("minPressure", minPressure_);
dict.readIfPresent("maxPressure", maxPressure_);
@@ -666,29 +678,39 @@ bool Foam::noiseModel::read(const dictionary& dict)
if (fLower_ < 0)
{
FatalIOErrorInFunction(dict)
- << "fl: lower frequency bound must be greater than zero"
+ << "Lower frequency bound must be greater than zero"
<< exit(FatalIOError);
}
if (fUpper_ < 0)
{
FatalIOErrorInFunction(dict)
- << "fu: upper frequency bound must be greater than zero"
+ << "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)"
+ << "Upper frequency bound (" << fUpper_
+ << ") must be greater than lower frequency bound ("
+ << fLower_ << ")"
<< exit(FatalIOError);
-
}
Info<< " Frequency bounds:" << nl
<< " lower: " << fLower_ << nl
- << " upper: " << fUpper_ << endl;
+ << " upper: " << fUpper_ << nl
+ << " sample: ";
+
+ if (sampleFreq_ > 0)
+ {
+ Info<< sampleFreq_ << nl;
+ }
+ else
+ {
+ Info<< "auto" << nl;
+ }
weightingTypeNames_.readIfPresent("SPLweighting", dict, SPLweighting_);
diff --git a/src/randomProcesses/noise/noiseModels/noiseModel/noiseModel.H b/src/randomProcesses/noise/noiseModels/noiseModel/noiseModel.H
index c3f1267e434..14c8d6db443 100644
--- a/src/randomProcesses/noise/noiseModels/noiseModel/noiseModel.H
+++ b/src/randomProcesses/noise/noiseModels/noiseModel/noiseModel.H
@@ -5,7 +5,7 @@
\\ / A nd | www.openfoam.com
\\/ M anipulation |
-------------------------------------------------------------------------------
- Copyright (C) 2015-2022 OpenCFD Ltd.
+ Copyright (C) 2015-2023 OpenCFD Ltd.
-------------------------------------------------------------------------------
License
This file is part of OpenFOAM.
@@ -34,8 +34,8 @@ Description
\verbatim
rhoRef 1;
N 4096;
- fl 25;
- fu 10000;
+ minFreq 25;
+ maxFreq 10000;
startTime 0;
outputPrefix "test1";
@@ -58,8 +58,9 @@ Description
Property | Description | Required | Default value
rhoRef | Reference density | no | 1
N | Number of samples in sampling window | no | 65536 (2^16)
- fl | Lower frequency bounds | no | 25
- fu | Upper frequency bounds | no | 10000
+ minFreq | Lower frequency bounds (fl) | no | 25
+ maxFreq | Upper frequency bounds (fu) | no | 10000
+ sampleFreq | Sample frequency | no | 0
startTime | Start time | no | 0
outputPrefix | Prefix applied to output files| no | ''
SPLweighting | Weighting: dBA, dBB, dBC, DBD | no | none
@@ -71,6 +72,9 @@ Description
writeOctaves | Write octaves data | no | yes
\endtable
+ If provided, the sampleFreq is used to define the deltaT between samples.
+ Otherwise the deltaT is determined from the time samples themselves.
+
SourceFiles
noiseModel.C
@@ -158,6 +162,9 @@ protected:
//- Upper frequency limit, default = 10kHz
scalar fUpper_;
+ //- Prescribed sample frequency
+ scalar sampleFreq_;
+
//- Start time, default = 0s
scalar startTime_;
diff --git a/src/randomProcesses/noise/noiseModels/pointNoise/pointNoise.C b/src/randomProcesses/noise/noiseModels/pointNoise/pointNoise.C
index 88b741efb9a..462abc3ba9f 100644
--- a/src/randomProcesses/noise/noiseModels/pointNoise/pointNoise.C
+++ b/src/randomProcesses/noise/noiseModels/pointNoise/pointNoise.C
@@ -101,7 +101,12 @@ void pointNoise::processData
Info<< "Creating noise FFT" << endl;
- const scalar deltaT = checkUniformTimeStep(t);
+ const scalar deltaT =
+ (
+ sampleFreq_ > 0
+ ? (1.0/sampleFreq_)
+ : checkUniformTimeStep(t)
+ );
// Apply conversions
p *= rhoRef_;
diff --git a/src/randomProcesses/noise/noiseModels/surfaceNoise/surfaceNoise.C b/src/randomProcesses/noise/noiseModels/surfaceNoise/surfaceNoise.C
index 806b815d817..fa4473ee4a6 100644
--- a/src/randomProcesses/noise/noiseModels/surfaceNoise/surfaceNoise.C
+++ b/src/randomProcesses/noise/noiseModels/surfaceNoise/surfaceNoise.C
@@ -5,7 +5,7 @@
\\ / A nd | www.openfoam.com
\\/ M anipulation |
-------------------------------------------------------------------------------
- Copyright (C) 2015-2022 OpenCFD Ltd.
+ Copyright (C) 2015-2023 OpenCFD Ltd.
-------------------------------------------------------------------------------
License
This file is part of OpenFOAM.
@@ -96,15 +96,21 @@ void surfaceNoise::initialise(const fileName& fName)
// Note: all processors should call the windowing validate function
label nRequiredTimes = windowModelPtr_->validate(nAvailableTimes);
- if (Pstream::master())
+ if (UPstream::master())
{
// Restrict times
- times_.setSize(nRequiredTimes);
- forAll(times_, timeI)
+ times_.resize_nocopy(nRequiredTimes);
+ forAll(times_, timei)
{
- times_[timeI] = allTimes[timeI + startTimeIndex_].value();
+ times_[timei] = allTimes[timei + startTimeIndex_].value();
}
- deltaT_ = checkUniformTimeStep(times_);
+
+ deltaT_ =
+ (
+ sampleFreq_ > 0
+ ? (1.0/sampleFreq_)
+ : checkUniformTimeStep(times_)
+ );
// Read the surface geometry
// Note: hard-coded to read mesh from first time index
--
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