Incompatible dimensions for operation
 

Hi friends,
I tried to combine solvers settlingFoam and bubbleFoam, I could compile successfully, bu when I ran my solver, which gives error, which states,
incompatible dimensions for operation
[alpha[0 0 -1 0 0 0 0] ] + [alpha[1 -3 -1 0 0 0 0] ]#0 Foam::error::printStack(Foam::Ostream&) in "/home/baburao/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libOpenFOAM.so"
#1 Foam::error::abort() in "/home/baburao/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libOpenFOAM.so"
#2 void Foam::checkMethod<double>(Foam::fvMatrix<double> const&, Foam::fvMatrix<double> const&, char const*) in "/home/baburao/OpenFOAM/OpenFOAM-1.5/applications/bin/linux64GccDPOpt/comsol"
#3 Foam::tmp<Foam::fvMatrix<double> > Foam::operator+<double>(Foam::tmp<Foam::fvMatrix<d ouble> > const&, Foam::tmp<Foam::fvMatrix<double> > const&) in "/home/baburao/OpenFOAM/OpenFOAM-1.5/applications/bin/linux64GccDPOpt/comsol"
#4 main in "/home/baburao/OpenFOAM/OpenFOAM-1.5/applications/bin/linux64GccDPOpt/comsol"
#5 __libc_start_main in "/lib/libc.so.6"
#6 _start at /build/buildd/glibc-2.9/csu/../sysdeps/x86_64/elf/start.S:116


From function checkMethod(const fvMatrix<Type>&, const fvMatrix<Type>&)
in file /home/baburao/OpenFOAM/OpenFOAM-1.5/src/finiteVolume/lnInclude/fvMatrix.C at line 1184.

FOAM aborting


Can anyone help with this errorsince I am very new to OpenFoam and C++,

Thanks in advance,

Anticipating for your kind reply,

Pramod

I guess there is problem with "rho" could u write the alphaEqn

Sachin

alphaEqn has been attached,

Thanks for your response Sachin

Pramod

You're obviously using the compressible formulation of 'phi', which includes the density, and that's why you have a dimensions mismatch.
Before 'sticking' codes together, make sure you know exactly what equations you are solving for. If you look at the difference between the alphaEqn in settlingFoam and bubbleFoam the reason it isn't working should be obvious.

yes , as I mentioned since I dont know C++ upto the mark , I tried to stick with the solvers. Sorry to tell this, can anyone help me regarding this,

Thanks in advance,
:mad:

This doesn't have anything to do with C++. I am assuming that you are solving:

fvm::ddt(alpha) + fvm::div(phi,alpha) + whatever

The problem you have is that your dimensions are different. alpha is dimensionless so the first term will have a dimension of . The second term has phi, which has dimensions of , and alpha which is dimensionless, so that term should also have dimensions of .

You are calculating phi using something akin to rho*U, which means your phi has different dimensions to the phi in the equation above.

Is your case compressible/incompressible?

In bubbleFoam the flux is volumetric:

phia = fvc::interpolate(Ua) & mesh.Sf();

in settlingFoam phi is created with compressibeCreatePhi.H in createFields.H

What is the purpose of combining these two codes?

Firstly thank you very much for your patient response Laurence, its helping me

I am solving with incompressible fluids,
I am open for any suggesstion

Thank you

Thanks alberto for your response, I am trying to combine the codes since my case has both setlingFoam n bubbleFoam involved,

Any suggestions are welcome,
Thank you