[Andy Somogyi]

Hey all, trying to output the flow rate though a patch. It works fine from the command line like:

postProcess -func 'flowRatePatch(name=ex)'

However if I put it in the controlDict in functions block like:


functions
{
#includeFunc flowRatePatch(name=ex)
}



I get the error that it can't find the 'phi' field when using the 'postProcess' command:

Reading fields:

Executing functionObjects
surfaceFieldValue flowRatePatch(name=ex) write:
total faces = 806
total area = 0.0008833

--> FOAM Warning :
From Foam::label Foam::functionObjects::fieldValues::surfaceFieldVa lue::writeAll(const vectorField&, const Foam::Field<Type>&, const pointField&, const faceList&) [with WeightType = double; Foam::label = int; Foam::vectorField = Foam::Field<Foam::Vector<double> >; Foam:ointField = Foam::Field<Foam::Vector<double> >; Foam::faceList = Foam::List<Foam::face>]
in file fieldValues/surfaceFieldValue/surfaceFieldValueTemplates.C at line 381
Requested field phi not found in database and not processed



How do I fix the controlDict so that postProcess works right?

thanks

[LongGe]

Hi

How about doing the following?

$ <using solver name> -postprocess -func 'flowRatePatch(name=ex)'

For example using simpleFoam
$ simpleFoam -postprocess -func 'flowRatePatch(name=ex)'

[Andy Somogyi]

Originally Posted by LongGe

Hi

How about doing the following?

$ <using solver name> -postprocess -func 'flowRatePatch(name=ex)'

For example using simpleFoam
$ simpleFoam -postprocess -func 'flowRatePatch(name=ex)'

That does work, along with just

"postprocess -func 'flowRatePatch(name=ex)"

But I'd like to add more functions to the controlDict, and I'm trying to figure out why the 'phi' field doesn't seem to be available for controlDict post process functions, when run with the "postProcess" command.

[LongGe]

Hi



The answer can be found here. "6.2.4 Solver post-processing" as https://doc.cfd.direct/openfoam/user...processing-cli

[chc]

What is the difference between using just postProcess -func functionObjectDict as opposed to the longer solverName -postProcess -func functionObjectDict ? For some reason I'm having some processes work with one or the other, and I'm not sure why

[Yann]

With solverName -postProcess, the solver starts, loads the required model, and does the post processing operations.

postProcess is an standalone application which will basically read the variables and do the post processing operations.

Some function objects are just doing operations on variables, others require access to data related to models used by the solvers. For the latter, postProcess will fail because the required models are not loaded by postProcess.

For instance, you cannot use the yPlus function object with postProcess because it requires to access to the turbulence model.

AFAIK, everything you can do with postProcess should also work with solverName -postProcess. Or at least I don't really see why it would not.