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-   -   Does someone has the same problem (https://www.cfd-online.com/Forums/openfoam-bugs/62394-does-someone-has-same-problem.html)

 ivanyao October 20, 2008 21:30

hi, i am simulating wind pres

hi,
i am simulating wind pressure on a cube.everything is fine,but when i calculated,it appeared sth wrong. like that;
Create mesh for time = 0
> Reading/calculating face flux field phi
> Selecting incompressible transport model Newtonian
> Selecting turbulence model kEpsilon
> Starting time loop
> Time = 0.005
> Courant Number mean: 0 max: 0.0774444
> DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual =
2.04207e-09, No Iterations 1
> DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual =
4.95291e-09, No Iterations 1
> DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual =
4.73817e-09, No Iterations 1
> --> FOAM FATAL ERROR : Continuity error cannot be removed by
> Please check the velocity boundary conditions and/or run
potentialFoam to initialise the outflow.
> Total flux : 971.7
> Specified mass inflow : 50184
> Specified mass outflow : 0
> Adjustable mass outflow : 0
> From function adjustPhi(surfaceScalarField& phi, const
volVectorField& U,const volScalarField& p
> FOAM exiting
does someone has the same problem?how to fix it?

 dbxmcf October 20, 2008 23:58

hi, there must be something wr

hi, there must be something wrong with your boundary condition, maybe no fixedValue pressure boundary for both inlet and outlet, search the error "Continuity error cannot be removed by adjusting the outflow", I remember this has been discussed several times.

 ivanyao October 21, 2008 10:16

hi, thank you!i will check it

hi,
thank you!i will check it.

 ivanyao October 22, 2008 21:04

hi, when i set fixedValue pre

hi,
when i set fixedValue pressure boundary for both inlet and outlet.and then calculate.it also appeared some errors:
Create mesh for time = 0

Selecting incompressible transport model Newtonian
Selecting turbulence model kEpsilon

Starting time loop

Time = 0.005

Courant Number mean: 0 max: 0.0774444
DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 2.04207e-09, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 4.95291e-09, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual = 4.73817e-09, No Iterations 1
DICPCG: Solving for p, Initial residual = 1, Final residual = 9.37246e-07, No Iterations 300
time step continuity errors : sum local = 1.70147e-10, global = 1.95661e-12, cumulative = 1.95661e-12
DICPCG: Solving for p, Initial residual = 7.43961e-05, Final residual = 9.77997e-07, No Iterations 120
time step continuity errors : sum local = 1.61161e-10, global = 1.48469e-11, cumulative = 1.68035e-11
#0 Foam::error::printStack(Foam:http://www.cfd-online.com/OpenFOAM_D...part/proud.gifstream&) in "/home/ivan/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/home/ivan/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libOpenFOAM.so"
#2 Uninterpreted: [0xb7fae420]
#3 Foam::divide(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) in "/home/ivan/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libOpenFOAM.so"
#4 void Foam::divide<foam::fvpatchfield,>(Foam::GeometricF ield<double,>&, Foam::GeometricField<double,> const&, Foam::GeometricField<double,> const&) in "/home/ivan/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libincompressibleTurbulenc eModels.so"
#5 Foam::tmp<foam::geometricfield<double,> > Foam::operator/<foam::fvpatchfield,>(Foam::tmp<foam::geometricfie ld<double,> > const&, Foam::GeometricField<double,> const&) in "/home/ivan/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libincompressibleTurbulenc eModels.so"
#6 Foam::turbulenceModels::kEpsilon::correct() in "/home/ivan/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libincompressibleTurbulenc eModels.so"
#7 main in "/home/ivan/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linuxGccDPOpt/turbFoam"
#8 __libc_start_main in "/lib/libc.so.6"

where did me make mistake?

 su_junwei October 23, 2008 16:00

hi weihong This may be caus

hi weihong

This may be caused by the exception of divide operator. Divide by zero for instance.

Junwei Su

 ivanyao October 26, 2008 09:20

hi， I am sorry, but I can n

hi，
I am sorry, but I can not understand what's the problem exactly。would you tell me in detail.it is important to me.thank you.

 su_junwei October 27, 2008 05:16

Dear weihong Run the a

Dear weihong

Run the application in gdb, and using the command "bt" (backtrace) to judge where such a exception occurred.

Also, try setting the fixed value boundary for inlet and zero gradient for outlet for the pressure p.

Junwei Su

 ivanyao October 27, 2008 06:14

hi,junwei thank you,i will tr

hi,junwei
thank you,i will try it.

 cwang5 October 27, 2008 08:49

Hi Weihong, I believe your

Hi Weihong,

I believe your problem is caused by your boundary condition setup. Please refer to the PitzDaily tutorial in simpleFoam for the proper boundary condition for inlet and outlet.

btw, I think this post should be in the general OpenFoam forum instead of the bug forum.

Hope that helps.

John

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