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July 11, 2012, 17:22 
Problem: Defining a linear scalar BC with groovyBC

#1 
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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 zaxis). 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: Code:
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; } 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. Code:
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // 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 } holp 

July 14, 2012, 06:30 

#2  
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Bernhard Gschaider
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July 19, 2012, 08:46 

#3 
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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 

July 19, 2012, 20:19 

#4  
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Bernhard Gschaider
Join Date: Mar 2009
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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/openfoamextendMantis low is important to my ego) 

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