CFD Online Discussion Forums - Problem using postProcess streamFunction

Hello everyone,

I'm quite new to CFD. I have run a simulation for a 2D domain (backward facing step). I am trying to calculate the stream function using the post processing functionality of openFoam. I write:

Code:

postProcess -func "streamFunction(U)"

As I've understood it, this is the correct syntax, though I'm not quite sure.

This runs, but at each timestep I get the following (with only the time being different):

Code:

Time = 0.01s



Reading fields:

    volVectorFields: U



Executing functionObjects

--> FOAM Warning :     functionObjects::streamFunction streamFunction(U) cannot find required object U of type surfaceScalarField

--> FOAM Warning :     functionObjects::streamFunction streamFunction(U) failed to execute.

This runs without returning an error, however I don't get any output. At least not that I can see in the different time folders.

I also tried writing this:

Code:

postProcess -func "streamFunction"

but this returns with an error:

Code:

Create time



Create mesh for time = 0



Time = 0s



Reading fields:



Executing functionObjects

--> FOAM Warning :     functionObjects::streamFunction streamFunction cannot find required object phi of type surfaceScalarField

--> FOAM Warning :     functionObjects::streamFunction streamFunction failed to execute.



Time = 0.0002s



Reading fields:

    surfaceScalarFields: phi



Executing functionObjects

#0  Foam::error::printStack(Foam::Ostream&) at ??:?

#1  Foam::sigFpe::sigHandler(int) at ??:?

#2  ? in "/lib/x86_64-linux-gnu/libc.so.6"

#3  Foam::Field<Foam::Vector<double> >::operator/=(Foam::tmp<Foam::Field<double> > const&) at ??:?

#4  Foam::functionObjects::streamFunction::calc(Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&) const at ??:?

#5  Foam::functionObjects::streamFunction::calc() at ??:?

#6  Foam::functionObjects::fieldExpression::execute() at ??:?

#7  Foam::functionObjects::timeControl::execute() at ??:?

#8  Foam::functionObjectList::execute() at ??:?

#9  ? in "/opt/openfoam10/platforms/linux64GccDPInt32Opt/bin/postProcess"

#10  ? in "/opt/openfoam10/platforms/linux64GccDPInt32Opt/bin/postProcess"

#11  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"

#12  ? in "/opt/openfoam10/platforms/linux64GccDPInt32Opt/bin/postProcess"

 Floating point exception

Which seems less correct.

Does anyone know what the problem is and how to fix it? Or alternatively, is there another way to calculate the stream function which is easier to use?
I have tried googling around, but couldn't find anyone with the same/similar problem. I also couldn't find any specific guides for streamFunction.

Any help would be appreciated! :)

Best regards,
Bendik