How to sample during run
 

Is there a way to run "sample" during a run? For example, I would like to monitor mdot through an inlet and create an animation of a 2D plane slice every 10 or so timesteps. However, to do this with a post-processing sample, I would be required to write the entire case every 10 timesteps and then run sample in the end - which is a lot of storage required.

Thanks,
Jason

Since 1.5 there is a functionObject that does exactly that. I think it is called surfaces

Bernhard

Yes, the surfaces function worked great for getting animations during runtime instead of post-process. Also the simpleFunctionObjects works great to do things like mass flow and pressure averages.

Thanks!
Jason

Hi Jason,

I'm trying to use the surfaces functionObject but have been unable to figure out the syntax for the controlDictionary. Could you post a quick example.

Thanks in advance,

-Mike

In system/controlDict, try to add a new section like:

functions
{
animate
{
type surfaces;
functionObjectLibs ("libsampling.so");
outputControl timeStep;
outputInterval 50;
surfaceFormat vtk;
interpolationScheme cellPointFace;

fields
(
p
U
);
surfaces
(
aplane
{
type plane;
basePoint (0.0 0.0 0.0);
normalVector (0.0 0.0 1.0);
}
pressure_inlet_001
{
type patch;
patchName pressure_inlet_001;
}
);
}

//for the simpleFunction - which you have to download this separately
massFlow
{
type patchMassFlow;
functionObjectLibs ("libsimpleFUnctionObjects.so");
verbose true;
outputControl timeStep;
outputInterval 1;
patches
(
pressure_inlet_001
pressure_outlet
);
};

//another simpleFunction
patchAverage
{
type patchAverage;
functionObjectLibs ("libsimpleFunctionObjects.so");
verbose true;
outputControl timeStep;
outputInterval 1;
patches
(
pressure_inlet_001
pressure_outlet
);
fields
(
p
U
);
}
}

Thanks Jason, worked perfectly.

sampling for Lagrangian particle tracking
 

Is there a similar sampling tool for Lagrangian particles ? i.e, I would
like to collect particle statistics such as mean particle size, mean
particle velocity etc., at an arbitrary surface inside the domain ?

Please let me know

Thanks
Vaidya