[jmmeena]

Compiled successfully but during running the case this error came:
Starting time loop

Time = 0.01

DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 8.03917e-06, No Iterations 4
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 8.25025e-06, No Iterations 4
DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual = 6.78799e-07, No Iterations 5
DILUPBiCG: Solving for h, Initial residual = 1, Final residual = 8.7112e-06, No Iterations 5
DICPCG: Solving for pd, Initial residual = 1, Final residual = 6.39622e-09, No Iterations 404
time step continuity errors : sum local = 2.35897e-11, global = 7.22445e-14, cumulative = 7.22445e-14
rho max/min : 5.28627 0.726473


incompatible dimensions for operation
[T[0 0 -1 1 0 0 0] ] + [T[1 -3 -1 1 0 0 0] ]#0 Foam::error:rintStack(Foam::Ostream&) in "/usr/lib/OpenFOAM-1.5/lib/libOpenFOAM.so"
#1 Foam::error::abort() in "/usr/lib/OpenFOAM-1.5/lib/libOpenFOAM.so"
#2 Foam::Ostream& Foam:perator<< <Foam::error>(Foam::Ostream&, Foam::errorManip<Foam::error>) at /usr/lib/OpenFOAM-1.5/src/OpenFOAM/lnInclude/errorManip.H:87
#3 void Foam::checkMethod<double>(Foam::fvMatrix<double> const&, Foam::fvMatrix<double> const&, char const*) at /usr/lib/OpenFOAM-1.5/src/finiteVolume/lnInclude/fvMatrix.C:1191
#4 Foam::tmp<Foam::fvMatrix<double> > Foam:perator+<double>(Foam::tmp<Foam::fvMatrix<d ouble> > const&, Foam::tmp<Foam::fvMatrix<double> > const&) at /usr/lib/OpenFOAM-1.5/src/finiteVolume/lnInclude/fvMatrix.C:1531
#5 main at ~OpenFOAM/jagmohan-1.5/applications/solvers/Scalar_Transport_combinations/buoyantTransportSimpleFoamNew/buoyantTransportSimpleFoamNew.C:78
#6 __libc_start_main in "/lib/libc.so.6"
#7 _start in "/home/users/jagmohan//OpenFOAM/jagmohan-1.5/applications/bin/buoyantTransportSimpleFoamNew"


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

FOAM aborting

Abandon
jagmohan@biquad:/home/users/jagmohan/OpenFOAM/jagmohan-1.5/run/coude_diffusion_thermal$

[su_junwei]

Hi JM
the problem is located at the line 78 in buoyantTransportSimpleFoamNew.C. Check it please.

Junwei

[jmmeena]

Yes Mr. Jumwei, These are the lines where error occurred:

solve
(
fvm::ddt(T)
+ fvm::div(phi, T)
- fvm::laplacian(DT, T)
); // this is line 78

and error of mis match of dimension came in this transport equation. I am not understanding why this is so ? Therefore I asked units of phi. Actually by definition phi is U. So there should not be any dimension problem.

incompatible dimensions for operation
[T[0 0 -1 1 0 0 0] ] + [T[1 -3 -1 1 0 0 0]

ddt[T] : [0 0 -1 1 0 0 0]

But how, div(phi, T) : [1 -3 -1 1 0 0 0] if phi is U ??

It seems that phi has dimension of [1 -2 -1 0 0 0 0] which is density*velocity !!!(not as definition of phi !!) I tried to write U instead of phi but then it gave syntax error because U is vector:
buoyantTransportSimpleFoamNew.C:76: erreur: no matching function for call to ‘div(Foam::volVectorField&, Foam::volScalarField&)’

Please help regarding this. I would really be thankful to you.

JM

[su_junwei]

Hi JM

I think there should be a problem in your parameter DT demension. It should be divided by a rho dimension. Just like relation between dynamic viscosity and kinetic viscosity.

Junwei

[jmmeena]

incompatible dimensions for operation
[T[0 0 -1 1 0 0 0] ] + [T[1 -3 -1 1 0 0 0]

As there is + sign between then ..problem is with dimensions of phi. I have checked dimensions of DT they are suitable for transport equation.

However, I multiplied phi term by 1/rho and it worked. But at 10th iteration it gave error:

Time = 0.009

DILUPBiCG: Solving for Ux, Initial residual = 0.296946, Final residual = 9.82349e-07, No Iterations 4
DILUPBiCG: Solving for Uy, Initial residual = 0.722249, Final residual = 5.61724e-06, No Iterations 4
DILUPBiCG: Solving for Uz, Initial residual = 0.666469, Final residual = 5.15711e-06, No Iterations 4
DICPCG: Solving for pd, Initial residual = 0.910202, Final residual = 0.022805, No Iterations 1001
time step continuity errors : sum local = 6.76243e+10, global = 2.96929e+07, cumulative = 2.96929e+07
rho max/min : 1.68757e+13 -3.65665e+15
DILUPBiCG: Solving for T, Initial residual = 0.889206, Final residual = 424.999, No Iterations 1001
DILUPBiCG: Solving for W, Initial residual = 6.48371e-05, Final residual = 0.000274964, No Iterations 1001
#0 Foam::error:rintStack(Foam::Ostream&) in "/usr/lib/OpenFOAM-1.5/lib/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/usr/lib/OpenFOAM-1.5/lib/libOpenFOAM.so"
#2 ?? in "/lib/libc.so.6"
#3 Foam:ILUPreconditioner::calcReciprocalD(Foam::Fi eld<double>&, Foam::lduMatrix const&) in "/usr/lib/OpenFOAM-1.5/lib/libOpenFOAM.so"
#4 Foam:ILUPreconditioner:ILUPreconditioner(Foam: :lduMatrix::solver const&, Foam::Istream&) in "/usr/lib/OpenFOAM-1.5/lib/libOpenFOAM.so"
#5 Foam::lduMatrix:reconditioner::addasymMatrixCons tructorToTable<Foam:ILUPreconditioner>::New(Foam ::lduMatrix::solver const&, Foam::Istream&) in "/usr/lib/OpenFOAM-1.5/lib/libOpenFOAM.so"
#6 Foam::lduMatrix:reconditioner::New(Foam::lduMatr ix::solver const&, Foam::Istream&) in "/usr/lib/OpenFOAM-1.5/lib/libOpenFOAM.so"
#7 Foam::PBiCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/usr/lib/OpenFOAM-1.5/lib/libOpenFOAM.so"
#8 Foam::fvMatrix<double>::solve(Foam::Istream&) in "/usr/lib/OpenFOAM-1.5/lib/libfiniteVolume.so"
#9 Foam::lduMatrix::solverPerformance Foam::solve<double>(Foam::tmp<Foam::fvMatrix<doubl e> > const&) in "/home/users/jagmohan//OpenFOAM/jagmohan-1.5/applications/bin/buoyantTransportSimpleFoam"
#10 Foam::compressible::RASModels::kEpsilon::correct() in "/usr/lib/OpenFOAM-1.5/lib/libcompressibleRASModels.so"
#11 main in "/home/users/jagmohan//OpenFOAM/jagmohan-1.5/applications/bin/buoyantTransportSimpleFoam"
#12 __libc_start_main in "/lib/libc.so.6"
#13 _start in "/home/users/jagmohan//OpenFOAM/jagmohan-1.5/applications/bin/buoyantTransportSimpleFoam"
Exception en point flottant

jagmohan@biquad:/home/users/jagmohan/OpenFOAM/jagmohan-1.5/run/coude_diffusion_thermal$


Now struggling with this. If you have any idea to remove this kind of computational error then please put your views. Anyways discussion really helped me a lot to reach at this level. Thank you very much !!

JM

[su_junwei]

Hi JM

your simulation diverged. this can be caused by many many reasons. If the solver was correctly written, bad boundary settings may be the primary problems.

Junwei

[jmmeena]

Can you comment on how rho is defined in buoyantSimpleFoam in creatField file ? It is defined as :

volScalarField rho
(
IOobject
(
"rho",
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::NO_WRITE
),
thermo->rho()
);

I don't understand why it is defined as No Read and No Write. And where is the value of rho defined. I am unable to find it in code or case !!
In addition can you tell me what rho max/min value shows during computation. It keeps changing but I think it should not change !!!
Please comment on this ! Thank you very much !!

JM

[su_junwei]

Hi JM
BuoyantSimpleFoam is a compressible solver. Temperature difference incurs density difference and following fluid flow. The density will change, and it is a main driven force for fliud flow.
rho is obtain from basicThermo class, and update rho every time step. See the pEqn.H:51.

Junwei

[jmmeena]

okay !!

Thank you very much for your valuable time.

[idrama]

Hello Fomers,

does anybody know why non-orthogonal steps must be performed. I do not understand the algorithm in this way.