[holp]

Hello everybody,

I'm new in this forum, so first: greetings everyone
Im currently in my 4th semester and was assigned a project which mainly involves openFoam. I was hoping you could help me with a problem, it would be very much appreciated.

I have to define a linear temperature distribution as B.C. over the lateral surface of a cylinder (along the z-axis). Since I couldn't find any tutorial how to adapt / write my own B.C. (it's also a bit complicated for a beginner), I wanted to use groovyBC in order to define the boundary condition.

My problem: it doesn't work. Or put another way: I screwed something up.
I downloaded the swak4Foam GNU tarball, executed wmake all and added
libs ("libOpenFOAM.so""libgroovyBC.so");
to my controlDict.

I then tried to define my B.C in the 0/T file:

surface
     {
         type     groovyBC;
         variables "zp = pos().z; m = pts().z ;minZ = min(m); maxZ =max(m)";
         valueExpression "200 + (zp) / (maxZ - minZ)) * 100";
         value uniform 1;
     }

I also tried some simpler variants variants, like
valueExpression "100*pos().z";
and used the mag() function since I wasn't enterely sure whether I was dealing with scalar values. Nothing worked.

When I execute paraFoam before calculating anything, the default value uniform 1 is always being used. Executing my modified IcoFoam solver, openFoam gives a bug report and crashes.

    // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0

Reading transportProperties

Reading field p

Reading field T

Reading field U

Reading/calculating face flux field phi


Starting time loop

Time = 1

Courant Number mean: 0 max: 0
DILUPBiCG:  Solving for Ux, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG:  Solving for Uy, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG:  Solving for Uz, Initial residual = 0, Final residual = 0, No Iterations 0
DICPCG:  Solving for p, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0, global = 0, cumulative = 0
DICPCG:  Solving for p, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0, global = 0, cumulative = 0
word::stripInvalid() called for word zp
    For debug level (= 2) > 1 this is considered fatal

}

I would appreciate any help / advise. Thanks a lot in advance.

holp

[gschaider]

Originally Posted by holp

Hello everybody,

I'm new in this forum, so first: greetings everyone
Im currently in my 4th semester and was assigned a project which mainly involves openFoam. I was hoping you could help me with a problem, it would be very much appreciated.

I have to define a linear temperature distribution as B.C. over the lateral surface of a cylinder (along the z-axis). Since I couldn't find any tutorial how to adapt / write my own B.C. (it's also a bit complicated for a beginner), I wanted to use groovyBC in order to define the boundary condition.

My problem: it doesn't work. Or put another way: I screwed something up.
I downloaded the swak4Foam GNU tarball, executed wmake all and added
libs ("libOpenFOAM.so""libgroovyBC.so");
to my controlDict.

I then tried to define my B.C in the 0/T file:

surface
     {
         type     groovyBC;
         variables "zp = pos().z; m = pts().z ;minZ = min(m); maxZ =max(m)";
         valueExpression "200 + (zp) / (maxZ - minZ)) * 100";
         value uniform 1;
     }

I also tried some simpler variants variants, like
valueExpression "100*pos().z";
and used the mag() function since I wasn't enterely sure whether I was dealing with scalar values. Nothing worked.

When I execute paraFoam before calculating anything, the default value uniform 1 is always being used.

That's alright I'm afraid: paraview does not know how to interpret groovyBC and therefor uses the old value (subsequent timesteps will always get value written and therefor be useful)

Originally Posted by holp

Executing my modified IcoFoam solver, openFoam gives a bug report and crashes.

    // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0

Reading transportProperties

Reading field p

Reading field T

Reading field U

Reading/calculating face flux field phi


Starting time loop

Time = 1

Courant Number mean: 0 max: 0
DILUPBiCG:  Solving for Ux, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG:  Solving for Uy, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG:  Solving for Uz, Initial residual = 0, Final residual = 0, No Iterations 0
DICPCG:  Solving for p, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0, global = 0, cumulative = 0
DICPCG:  Solving for p, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0, global = 0, cumulative = 0
word::stripInvalid() called for word zp
    For debug level (= 2) > 1 this is considered fatal

}

I would appreciate any help / advise. Thanks a lot in advance.

holp

My bad: you tried to make it more readable by adding spaces. Now swak4Foam uses the variable name "zp " and OpenFOAM does not think this is a word. It occurred once before and I meant to fix this but I forget about such SEPs ("Somebody elses problem") if they are not in the Mantis. So for the time being remove the space before the = and you should be fine

[holp]

Thank you very much for your answer, and also my apologies for answering one week late.

I managed to get it running by not defining the variables and only using the valueExpression term. But it's always good to know what caused the problem - might save me quite some trouble in the future.
I didn't expect that problem, because every (programming) language I ever dealt with absolutely ignores blank spaces.

You programmed swak4Foam? Respect, and thanks a lot!

holp

[gschaider]

Originally Posted by holp

Thank you very much for your answer, and also my apologies for answering one week late.

I managed to get it running by not defining the variables and only using the valueExpression term. But it's always good to know what caused the problem - might save me quite some trouble in the future.
I didn't expect that problem, because every (programming) language I ever dealt with absolutely ignores blank spaces.

You're right (although one might say: Fortran 77 and Python take spaces very seriously. For different reasons ... and in one case I'd say: for good reasons). And swak ignores spaces everywhere else. But that part (variables) was a bit of an afterthought. And I'm a bit stubborn there: either a client demands a fix from me there or someone takes the time to write a bug report on the Mantis before I fix it

Originally Posted by holp

You programmed swak4Foam? Respect, and thanks a lot!

You're welcome. And as I said above: best "Thank you" is writing precise bug report on the Mantis, because the only three priorities for me to improve swak are: client demands, stuff that interests me and stuff that touches my ego (and keeping the number of bugs in the swak/openfoam-extend-Mantis low is important to my ego)