CFD Online Discussion Forums - Using .stl - Surface for Average Pressure / Mass Flux / ...

Dear Reader,

I made a pipe with blockMesh where I want to implement some .stl - surfaces , where I can analyze for example the average pressure , mass flux, mean temperature etc. during my calculations (not in post-processing).

I tried to use the tutorial snappyMultiRegionHeater as help:

First I created a .stl -surface in Ansa. Then I created a dictionary in the constant dictionary called triSurface, where I have put my .stl file

Questions

1) Overall: Do I have to use snappyhexmesh or is it possible to do it without snappy . That means: Do I have to mesh my .stl surface file or is it enough just to create a directory with the .stl file?

2) Since it is only used for analyzing: do I have to create a dictionary in the constant directory with files for turbulenceproperties, RasProperties, ... for the .stl surface? Actually I would not know what kind of entries I should add in those files, because it's just for analyzing data.

3) I am trying to implement the analyzing of the surface in the ControlDict using swak4Foam :

Code:

/*--------------------------------*- C++ -*----------------------------------*\

| ========= | |

| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |

| \\ / O peration | Version: 2.4.0 |

| \\ / A nd | Web: www.OpenFOAM.org |

| \\/ M anipulation | |

\*---------------------------------------------------------------------------*/

FoamFile

{

version 2.0;

format ascii;

class dictionary;

location "system";

object controlDict;

}

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

//"libtabulatedHeatTransferMassFlow.so"

libs (

//"libtabulatedHeatTransferMassFlow.so"

"libfieldFunctionObjects.so"

"libsimpleSwakFunctionObjects.so"

"libswakFunctionObjects.so"

"libgroovyBC.so"

);

application rhoPorousSimpleFoam;

startFrom startTime;

startTime 0;

stopAt endTime;

endTime 500;

deltaT 1;

writeControl timeStep;

writeInterval 100;

purgeWrite 0;

writeFormat binary;

writePrecision 6;

writeCompression off;

timeFormat general;

timePrecision 6;

graphFormat raw;

runTimeModifiable true;

　

// ************************************************************************* //

functions

(

PressureBefore

{

type swakExpression;

outputControlMode timeStep;

outputInterval 1;

valueType surface;

surfaceName ControlSurfaceHWTEinlass;

surface {

type sampledTriSurfaceMesh;

surface ControlSurfaceHWTEinlass.stl;

source cells; // What to sample: cells (nearest cell)



interpolate false;

}

expression "p";

accumulations (average);

verbose true;

} 

);

Could this work like this?

Thank you in advance