this->refValue()[faceI] = ??
 

Dear OF users,

as mentioned in my last post, I am doing a coupling between OF and another programm with pvm. http://www.cfd-online.com/Forums/ope...m-pvm-how.html
I modified the transferData() in externalCoupledTemperatureMixedFvPatchScalarField. C and readData() in externalCoupledMixedFvPatchField.C with pvm data transfer. After some debugging the code finally works. Now I face a new problem in externalCoupledMixedFvPatchField.C:

// so it receives a double temp[faceI] for example:
pvm_recv(tid, faceI);
pvm_upkdouble(&temp[faceI],1,1);
// how do I get this double temp[faceI] into refValue()[faceI] ??
this->refValue()[faceI] = ??

I was trying to send tempratures to this .so, so it is just a scalar.
I appreciate any advices.
peter

Greetings Peter,

I'm having a bit of difficulty understanding your question.
Because, the answer seems to be as simple as:
But I can only assume that you tried this and it didn't work?
If it didn't, then please provide more information.

Best regards,
Bruno

Hi Bruno, thanks for your reply!
I tried that option already - right at the beginning. But it that solution is too nice and simple to be right.
Here is the error message from wmake:
So after that I just followed my feelings and tried different things out. Nothing worked out yet. I commented out all the different things I tried in the following code.
Almost all errors told me that the types did not match each other. I am still learning c++ programming and openfoam source code. This problem is way beyond my level at the moment...:confused:

By the way, this is the only one that worked until now. But this does not help me much.

this->refValue()[faceI] = pTraits<Type>::zero;

The error seems to indicate that you are trying to assign a double to vector double (or vice-versa). How is temp read in and what does it contain?

pvm_upkdouble(&temp[faceI],1,1);
With this function pvm would assign the unpacked double value to temp[faceI],
so temp[0], temp[1], temp[3] ... are just single double values, like 312.99
I also tried this->refValue()[faceI] = some vector double, it did not work either.

I figured out a real dummy solution for my problem.
I firstly use lockfile as an output file stream os:
os << temp[faceI]
then define lockfile as a input file stream is:
is >> this->refValue()[faceI]
and then os.flush()
I tested it and it worked out.

But this is really dummy. There must be a neater way.

[QUOTE=peteryuan;473162]
I think this error message mean you have to assign a Vector so something like
So you some have to transfer three values per face from one code to the other. Or if you transfer just the magnitude of the vector and the resulting vector should be orientated normal to the patch surface you could something like this:
This would set one value to the whole patch (temp would be one double value). If you want to assign individual values for each face you have to do something like this:
I am not sure how to get the face normal vectors, but this might help:
http://www.cfd-online.com/Forums/ope...tml#post424141
perhaps in your case:

Hi Joachim:
thank you so much for your help.

I added this two lins in my forAll loop:
Got a very familiar error:
Here the full error message:

Ok, could you try somethings:
I have programmed a new boundary conditions with this inheritance:
In this class I use the following code (to set the boundary values to all surfaces of a patch to one value:
I am not sure, if you need to add this-> before the functions calls to refValue() and valueFraction().

Does this work? What is the base class of your new boundary condition? The error messages point to some tensor class.

Thanks Joachim, I will try that.
Actually I did not know how to implement a new BC. So I simply backed up the original file and modified my src directory, then recompile.
"I modified the transferData() in externalCoupledTemperatureMixedFvPatchScalarField. C and readData() in externalCoupledMixedFvPatchField.C with pvm data transfer."
But I just found some tutorials on how ot do that more "properly". I might try to move my modified classe out of src and give them another name.

Now I have another question, which is more important for me:

How can I make heat flux external coupled like I did with tempratur? There is not even a qDot file in 0 dir...

just a quick feed back:
I have not tried this with a new class.
But if I put
this->refValue() = this->patch().nf() * temp[faceI];
in my old code, which assign a single value for the whole patch, I get the following message:
error: no match for ‘operator=’ (operand types are ‘Foam::Field<Foam::Tensor<double> >’ and ‘Foam::tmp<Foam::Field<Foam::Vector<double> > >’)
this->refValue() = this->patch().nf() * temp[faceI];

The boundary conditions of which field do you want to couple? Is it a tensor field? Does the coupling work for scalar fields (like p, T, ...)? Is your code based on http://foam.sourceforge.net/docs/cpp/a04346_source.html (line 391)?

yep, the receiving data part is based on that location. The sinding out data part is based on http://foam.sourceforge.net/docs/cpp/a09284_source.html on line
226 os << magSf[faceI] << token::SPACE
...
I need openfoam to receive temprature and heat flux as boundary condition from an external programm via pvm and send magSf, qDot and htc back to the external programm.
So T is a scalar field. Heat flux is a vector field. Right?
The sending out data part works pretty good already. The receiving data part works okay for temprature with my dummy solution through is and os. (we might be able to improve that later.)
Now I still do not know how to read in heat flux as a boudary condition from the external solver.

Hi,

I know this is an old post. But do you have any updates on how to assign the values to the refValue or refGrad in the BC file?

Thanks,
Rdf

----

So there is another way to work around the issue.
// reinitialize the refValue_ with all 1
refValue_= pTraits<Type>::one;

and then do the operation you want

refValue_ = refValue_* YourValue;