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Thin membrane using neumann conditions

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Old   October 28, 2013, 14:40
Default Thin membrane using neumann conditions
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Eng. Emmanuel Luján
Join Date: Mar 2013
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I have a problem, I need to model a very thin membrane using neumann conditions. I used Salome Meca to create a mesh with a small sphere inside a box. The membrane is a facezone in the surface of the sphere. I created two patches that are together (cell_membrane_m and cell_membrane_s) from this facezone using createBaffles. My problem is that now I have to put a neumann condition like this:

flux normal to the surface represented by cell_membrane_m =
= flux normal to the surface represented by cell_membrane_s=
= km * ( Potential (Vm) in cell_membrane_m - Potential (Vs) in cell_membrane_s )

(last term is the transmembrane potential)

Here is what I did:

type groovyBC;
variables "Vs{cell_membrane_s}=sum(V*mag(Sf()))/sum(mag(Sf()));km=0.01;Vm=sum(V*mag(Sf()))/sum(mag(Sf()));";
gradientExpression "km*(Vm-Vs)";
value uniform 0;
fractionExpression "0";
type groovyBC;
variables "Vm{cell_membrane_m}=sum(V*mag(Sf()))/sum(mag(Sf()));km=0.01;Vs=sum(V*mag(Sf()))/sum(mag(Sf()));";
gradientExpression "km*(Vm-Vs)";
value uniform 0;
fractionExpression "0";

As you can see I'm using groovyBC too.

I'm using my own solver, based in lapplacian calculations. But I don't think it is the problem because I used it with other examples and worked well.

The error I get is:

#0 Foam::error:rintStack(Foam::Ostream&) in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/"
#1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/"
#2 in "/lib/x86_64-linux-gnu/"
#3 double Foam::sumProd<double>(Foam::UList<double> const&, Foam::UList<double> const&) in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/"
#4 Foam::PCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/"
#5 Foam::fvMatrix<double>::solveSegregated(Foam::dict ionary const&) in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/"
#6 Foam::fvMatrix<double>::solve(Foam::dictionary const&) in "/opt/openfoam221/platforms/linux64GccDPOpt/bin/pnp"
#7 Foam::fvMatrix<double>::solve() in "/opt/openfoam221/platforms/linux64GccDPOpt/bin/pnp"
in "/opt/openfoam221/platforms/linux64GccDPOpt/bin/pnp"
#9 __libc_start_main in "/lib/x86_64-linux-gnu/"
in "/opt/openfoam221/platforms/linux64GccDPOpt/bin/pnp"
Excepción de coma flotante (`core' generado)

Can you help me please? Thank you!


PD: This is an image about the boundary condition I want to set:
elujan is offline   Reply With Quote


groovybc, neuman conditions, thin membrane

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