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ENH: Updated noise utility header documentation
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@ -27,118 +27,62 @@ Application
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Description
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Utility to perform noise analysis of pressure data.
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The utility provides a light wrapper around the run-time selectable
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noise model. Current options include:
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- point, and
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- surface
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models.
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\heading Usage
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\heading Example usage
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Control settings are read from the $FOAM_CASE/system/noiseDict dictionary,
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or user-specified dictionary using the -dict option. Presure data can be
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supplied as a single time history at a given point location, or a surface
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of time histories, based on the run-time selectable \c noiseModel, e.g.
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\vebatim
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noiseModel <geometryType>Noise;
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<geometryType>Coeffs
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{
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...
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}
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\endverbatim
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where \<geometryMode\> is either \c point or \surface
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Both operation types require:
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\verbatim
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pRef 101325;
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N 65536;
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fl 25;
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fu 10000;
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fftWriteInterval 1;
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dataMode point;
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\endverbatim
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noiseModel surfaceNoise; // pointNoise
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where
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\table
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Property | Description | Required | Default value
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pRef | Reference pressure | no | 0
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N | Number of samples in sampling window | no | 65536 (2^16)
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fl | Lower frequency band | no | 25
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fu | Upper frequency band | no | 10000
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fftWriteInterval | Output interval for FFT data | no | 1
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dataMode | Input data mode, 'point' or 'surface' | yes |
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\endtable
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Point-based pressure data is read using a CSV reader, and output in a
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graph format:
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\verbatim
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pointData
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surfaceNoiseCoeffs
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{
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csvFileData
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windowModel Hanning;
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HanningCoeffs
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{
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fileName "pressureData";
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nHeaderLine 1;
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refColumn 0;
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componentColumns (1);
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separator " ";
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mergeSeparators yes;
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// Window overlap percentage
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overlapPercent 50;
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symmetric yes;
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extended yes;
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// Optional number of windows, default = all available
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nWindow 5;
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}
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graphFormat raw;
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windowOverlapPercent 0;
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nWindow 100; // fixed number of windows
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// Input file
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inputFile "postProcessing/faceSource1/surface/patch/patch.case";
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// Surface reader
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reader ensight;
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// Surface writer
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writer ensight;
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// Collate times for ensight output - ensures geometry is only written once
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writeOptions
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{
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ensight
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{
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collateTimes 1;
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}
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}
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// Number of samples in sampling window
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// Must be a power of 2, default = 2^16 (=65536)
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N 4096;
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// Write interval for FFT data, default = 1
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fftWriteInterval 100;
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}
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\endverbatim
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where
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\table
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Property | Description | Required | Default value
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csvFileData | CSV file data dictionary - see CSV.H | yes |
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graphFormat | Output graph format | no | raw
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windowOverlapPercent | Window overla percent| yes |
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nWindow | Number of sampling windows | no | 1, calculated
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\endtable
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Surface-based pressure data is specified using a surface reader, and output
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using a surface writer. The reader type must support multiple time
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handling, e.g. the ensight format. Output surfaces are written on a
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per-frequency basis:
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\verbatim
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surfaceData
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{
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reader ensight;
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writer ensight;
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inputFile "postProcessing/faceSource1/surface/patch1/patch1.case";
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pName p;
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windowOverlapPercent 50;
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// nWindow 0; // let code decide if not present
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}
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\endverbatim
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where
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\table
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Property | Description | Required | Default value
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reader | Surface reader type | yes |
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writer | Surface writer type | yes |
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inputFile | Pressure data surface file | yes |
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pName | Name of pressure field | no | p
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windowOverlapPercent | Window overla percent| yes |
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nWindow | Number of sampling windows | no | 1, calculated
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\endtable
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Current outputs include:
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- FFT of the pressure data (Pf)
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- narrow-band PFL (pressure-fluctuation level) spectrum (Lf)
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- one-third-octave-band PFL spectrum (Ldelta)
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- one-third-octave-band pressure spectrum (Pdelta)
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Note:
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- If using the windowOverlapPercent entry, the code will automatically
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determine number of windows
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- However, if supplied, the nWindow entry will take precedence
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SeeAlso
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CSV.H
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surfaceReader.H
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surfaceWriter.H
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noiseFFT.H
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noiseModel.H
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windowModel.H
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