| LucasCosta |
September 12, 2016 09:49 |
Problems with mass flow rate, pressure and velocity average values
Hi people, I'm new in OpenFoam and a I have some problems, I want to know the pressure and velocity average, and the mass flow rate in a surface. This surface is an stl file, and I made it a faceZone using snappyHexMesh.
Code:
// Which of the steps to run
castellatedMesh true; // make basic mesh ?
snap true; // decide to snap back to surface ?
addLayers false; // decide to add viscous layers ?
geometry // Load in STL files here
{
TuboVenture.stl
{
type triSurfaceMesh;
name venture;
}
areaSaidaVenture.stl
{
type triSurfaceMesh;
name saida;
}
areaEntradaVenture.stl
{
type triSurfaceMesh;
name entrada;
}
};
castellatedMeshControls
{
maxLocalCells 2500000; //max cells per CPU core
maxGlobalCells 10000000; //max cells to use before mesh deletion step
minRefinementCells 10; //was 0 - zero means no bad cells are allowed during refinement stages
maxLoadUnbalance 0.10;
nCellsBetweenLevels 4; // expansion factor between each high & low refinement zone
features // taken from STL from each .eMesh file created by "SurfaceFeatureExtract" command
(
{
file "TuboVenture.eMesh";
level 5;
}
{
file "areaEntradaVenture.eMesh";
level 5;
}
{
file "areaSaidaVenture.eMesh";
level 5;
}
);
refinementSurfaces // Surface-wise min and max refinement level
{
venture
{
level (2 3);
patchInfo
{
type wall;
}
}
saida
{
level (1 2);
faceZone saidaV;
cellZone saidaV;
cellZoneInside inside;
boundary saidaV;
}
entrada
{
level (1 2);
faceZone entradaV;
cellZone entradaV;
cellZoneInside inside;
boundary entradaV;
}
}
resolveFeatureAngle 30; // Resolve sharp angles // Default 30
refinementRegions // In descending levels of fine-ness
{
}
locationInMesh (-9.12 -2.11 -2.14); //to decide which side of mesh to keep **
allowFreeStandingZoneFaces true;
}
// Settings for the snapping.
snapControls
{
nSmoothPatch 5;
tolerance 4.0;
nSolveIter 150;
nRelaxIter 8;
nFeatureSnapIter 10; // default is 10
// New settings from openfoam 2.2 onwards for SHMesh
implicitFeatureSnap false; // default is false - detects without doing surfaceFeatureExtract
explicitFeatureSnap true; // default is true
multiRegionFeatureSnap true; // deafault is false - detects features between multiple surfaces
}
// Settings for the layer addition.
addLayersControls //add the PATCH names from inside the STL file so STLpatchName_insideSTLName
{
relativeSizes false; // was true
layers
{
visc_main
{nSurfaceLayers 3;} // was 3
visc_refine_1
{nSurfaceLayers 3;} // was 3
visc_refine_2
{nSurfaceLayers 3;} // was 3
}
expansionRatio 1.3;
finalLayerThickness 0.00016; //was 0.00016
minThickness 0.00008; //was 0.00008
nGrow 0; // was 1
// Advanced settings
featureAngle 80; // was 70 //- When not to extrude surface. 0 is flat, 90 is right angle.
nRelaxIter 3; //- Max# of snapping relaxation iter. Should stop before upon reaching a correct mesh.
nSmoothSurfaceNormals 1; // Number of smoothing iterations of surface normals
nSmoothNormals 3; // Number of smoothing iterations of interior mesh movement direction
nSmoothThickness 10; // Smooth layer thickness over surface patches
maxFaceThicknessRatio 0.5; // Stop layer growth on highly warped cells
maxThicknessToMedialRatio 0.3; // Reduce layer growth where ratio thickness to medial distance is large
minMedianAxisAngle 130; // Angle used to pick up medial axis points
nBufferCellsNoExtrude 0; // Create buffer region for new layer terminations
nLayerIter 50; // Overall max number of layer addition iterations
}
// Generic mesh quality settings. At any undoable phase these determine
// where to undo.
meshQualityControls
{
maxNonOrtho 65;
maxBoundarySkewness 20;
maxInternalSkewness 4;
maxConcave 70;
minFlatness 0.5;
minVol 1e-13;
minTetQuality 1e-9;
minArea -1;
minTwist 0.02;
minDeterminant 0.001;
minFaceWeight 0.02;
minVolRatio 0.01;
minTriangleTwist -1;
// Advanced
nSmoothScale 4;
errorReduction 0.75;
}
// Advanced
debug 0;
// Merge tolerance. Is fraction of overall bounding box of initial mesh.
// Note: the write tolerance needs to be higher than this.
mergeTolerance 1E-6;
// ************************************************************************* //
After that I configurate my controlDict in this way
Code:
application simpleFoam;
startFrom startTime;
startTime 1000;
stopAt endTime;
endTime 2000;
deltaT 1;
writeControl timeStep;
writeInterval 100;
purgeWrite 0;
writeFormat binary;
writePrecision 6;
writeCompression off;
timeFormat general;
timePrecision 6;
runTimeModifiable true;
functions
{
massFlow
{
type faceSource;
functionObjectLibs ("libfieldFunctionObjects.so");
enabled true;
outputControl timeStep;
outputInterval 1;
// Output to log&file (true) or to file only
log true;
// Output field values as well
valueOutput false;
// Type of source: patch/faceZone/sampledSurface
source faceZone;
// if patch or faceZone: name of patch or faceZone
sourceName entradaV;
// Operation: areaAverage/sum/weightedAverage ...
operation sum;
surfaceFormat stl;
fields
(
phi
);
}
surfaceRegion1
{
type surfaceRegion;
libs ("libfieldFunctionObjects.so");
log yes;
writeArea yes;
writeFields true;
surfaceFormat none;
regionType faceZone;
name saidaV;
operation average;
fields
(
p
phi
U
);
}
surfaceRegion2
{
type surfaceRegion;
libs ("libfieldFunctionObjects.so");
log yes;
writeArea yes;
writeFields true;
surfaceFormat none;
regionType faceZone;
name entradaV;
operation sum;
fields
(
p
phi
U
);
}
}
// ************************************************************************* //
My geometry is this :
http://imgur.com/byToNs0
it's an external simulation through a circular pipe, and the blue lines in this view are my surfaces that I want to made the measures.
When I ran the simulation it goes ok, by I don't get any values that I want in the postProcessor folder, Can anyone help me?
Thanks for the attention and sorry if it's a silly doubt. |
