CFD Online Discussion Forums - Emptying of a tank

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Emptying of a tank

I want to simulate emptying of an air tank with 30L of air and initial pressure of 9 bar through a valve. The remaining boundary conditions on the otherside of the valve is atm pressure. Which solver and boundary condition is most approperiate for this? From the results im interested in pressure and velocities. The flow is completely driven of pressure difference and first thought was to use pisoFoam or pimpleFoam, but my main concerns is how to implement the boundary conditions.

Thanks in adavance!

Hey,

i'm sorry for not being able to answer ur which solver to take question. Both should work imho.

The boundary conditions i'd take for pressure: outlet (atmosphere?): totalpressure and for velocity pressureInletOutletVelocity

wall: pressure: zeroGradient, velocity: fixedValue

since i'm also pretty new to openfoam i hope i could help a little. For better help i guess u should give a little more information. I don't have the link now, but there's a thread explaining how to give enough information.

if u have already solved ur problem, then this answer can be ignored :)

Quote:

Originally Posted by Wokl (Post 470818)

Thanks for the suggetsion, i have a air tank where i set my pressure to 9 bar then i have a section with the valve and the outlet. On the outlet the static pressure is set to 1 bar and the remaining section have an initial pressure at 9 bar. I use rhoPimpleFoam as the solver. In my case i do not have any inlet.

have u already tried running the simulation? Any errors occured?

Quote:

Originally Posted by Wokl (Post 470838)

have u already tried running the simulation? Any errors occured?

Yes i implemented everything as you suggestions but i got this problem as well

From function janafThermo<EquationOfState>::limit(const scalar T) const
in file /disk/sw/OpenFOAM/OpenFOAM-2.2.2/src/thermophysicalModels/specie/lnInclude/janafThermoI.H at line 108
attempt to use janafThermo<EquationOfState> out of temperature range 200 -> 6000; T = -9594.63

it seems like my temperature diverge completely.

I include my files i dont know if you can see any critical issues. Thanks for the support =)

hey,

maybe trying to set temerature at outlet to inletoutlet instead of zerogradient. But this is just a guess. i dont really have experiences with temperature and compressible domains

have you tried sonicLiquidFoam? perhaps change the properties to Air?

i got this error message and it dosent seems to work even if i decrease the time step.

Code:

Courant Number mean: 2.546e-06 max: 2.102

Time = 7.44e-05

PIMPLE: iteration 1

DILUPBiCG:  Solving for Ux, Initial residual = 0.000198399, Final residual = 1.21462e-08, No Iterations 1

DILUPBiCG:  Solving for Uy, Initial residual = 1.532e-06, Final residual = 6.61833e-11, No Iterations 1

DILUPBiCG:  Solving for Uz, Initial residual = 0.000142973, Final residual = 1.4482e-08, No Iterations 1

DILUPBiCG:  Solving for h, Initial residual = 8.24238e-06, Final residual = 6.59127e-10, No Iterations 1

DICPCG:  Solving for p, Initial residual = 1.52383e-06, Final residual = 1.10028e-10, No Iterations 1

DICPCG:  Solving for p, Initial residual = 2.96936e-10, Final residual = 2.96936e-10, No Iterations 0

diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0

time step continuity errors : sum local = 2.23424e-08, global = 2.2295e-08, cumulative = 5.30414e-06

rho max/min : 16.9458 0.5

DICPCG:  Solving for p, Initial residual = 1.06662e-06, Final residual = 7.77725e-11, No Iterations 1

DICPCG:  Solving for p, Initial residual = 2.05943e-10, Final residual = 2.05943e-10, No Iterations 0

diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0

time step continuity errors : sum local = 2.23283e-08, global = 2.22954e-08, cumulative = 5.32643e-06

rho max/min : 16.9067 0.5

PIMPLE: iteration 2

DILUPBiCG:  Solving for Ux, Initial residual = 0.000190691, Final residual = 1.19965e-08, No Iterations 1

DILUPBiCG:  Solving for Uy, Initial residual = 1.46142e-06, Final residual = 6.30652e-11, No Iterations 1

DILUPBiCG:  Solving for Uz, Initial residual = 0.000138518, Final residual = 1.57799e-08, No Iterations 1

DILUPBiCG:  Solving for h, Initial residual = 5.76779e-06, Final residual = 5.30602e-10, No Iterations 1

DICPCG:  Solving for p, Initial residual = 1.10255e-06, Final residual = 7.86287e-11, No Iterations 1

DICPCG:  Solving for p, Initial residual = 2.16707e-10, Final residual = 2.16707e-10, No Iterations 0

diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0

time step continuity errors : sum local = 2.23301e-08, global = 2.22953e-08, cumulative = 5.34873e-06

rho max/min : 16.5248 0.5

DICPCG:  Solving for p, Initial residual = 7.70794e-07, Final residual = 5.57445e-11, No Iterations 1

DICPCG:  Solving for p, Initial residual = 1.4971e-10, Final residual = 1.4971e-10, No Iterations 0

diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0

time step continuity errors : sum local = 2.23196e-08, global = 2.22956e-08, cumulative = 5.37102e-06

rho max/min : 16.4998 0.5

PIMPLE: not converged within 2 iterations

ExecutionTime = 206.27 s  ClockTime = 206 s

Courant Number mean: 2.55218e-06 max: 2.36776

Time = 7.46e-05

PIMPLE: iteration 1

DILUPBiCG:  Solving for Ux, Initial residual = 0.000194144, Final residual = 1.20409e-08, No Iterations 1

DILUPBiCG:  Solving for Uy, Initial residual = 1.5305e-06, Final residual = 6.64108e-11, No Iterations 1

DILUPBiCG:  Solving for Uz, Initial residual = 0.000145038, Final residual = 9.4424e-08, No Iterations 1

DILUPBiCG:  Solving for h, Initial residual = 8.26599e-06, Final residual = 6.90078e-10, No Iterations 1

DICPCG:  Solving for p, Initial residual = 1.53046e-06, Final residual = 1.10175e-10, No Iterations 1

DICPCG:  Solving for p, Initial residual = 2.97131e-10, Final residual = 2.97131e-10, No Iterations 0

diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0

time step continuity errors : sum local = 2.09252e-08, global = 2.08779e-08, cumulative = 5.3919e-06

rho max/min : 15.9424 0.5

DICPCG:  Solving for p, Initial residual = 1.07098e-06, Final residual = 7.77815e-11, No Iterations 1

DICPCG:  Solving for p, Initial residual = 2.05442e-10, Final residual = 2.05442e-10, No Iterations 0

diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0

time step continuity errors : sum local = 2.0911e-08, global = 2.08783e-08, cumulative = 5.41278e-06

rho max/min : 15.9118 0.5

PIMPLE: iteration 2

DILUPBiCG:  Solving for Ux, Initial residual = 0.000187142, Final residual = 1.17762e-08, No Iterations 1

DILUPBiCG:  Solving for Uy, Initial residual = 1.46069e-06, Final residual = 6.29492e-11, No Iterations 1

DILUPBiCG:  Solving for Uz, Initial residual = 0.000141385, Final residual = 1.25737e-08, No Iterations 1

DILUPBiCG:  Solving for h, Initial residual = 5.83935e-06, Final residual = 5.25375e-10, No Iterations 1



[6] #0  Foam::error::printStack(Foam::Ostream&) in "/disk/sw/OpenFOAM/OpenFOAM-2.2.2/platforms/linux64Gcc45DPOpt/lib/libOpenFOAM.so"

[6] #1  Foam::sigFpe::sigHandler(int) in "/disk/sw/OpenFOAM/OpenFOAM-2.2.2/platforms/linux64Gcc45DPOpt/lib/libOpenFOAM.so"

[6] #2  __restore_rt at sigaction.c:0

[6] #3  Foam::hePsiThermo<Foam::psiThermo, Foam::pureMixture<Foam::sutherlandTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleEnthalpy> > > >::calculate() in "/disk/sw/OpenFOAM/OpenFOAM-2.2.2/platforms/linux64Gcc45DPOpt/lib/libfluidThermophysicalModels.so"

[6] #4  Foam::hePsiThermo<Foam::psiThermo, Foam::pureMixture<Foam::sutherlandTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleEnthalpy> > > >::correct() in "/disk/sw/OpenFOAM/OpenFOAM-2.2.2/platforms/linux64Gcc45DPOpt/lib/libfluidThermophysicalModels.so"

[6] #5  main in "/disk/sw/OpenFOAM/OpenFOAM-2.2.2/platforms/linux64Gcc45DPOpt/bin/rhoPimpleFoam"

[6] #6  __libc_start_main in "/lib64/libc.so.6"

[6] #7  _start in "/disk/sw/OpenFOAM/OpenFOAM-2.2.2/platforms/linux64Gcc45DPOpt/bin/rhoPimpleFoam"

Hey,

i might be very wrong with this cause i don't know how this solver works. Ur courant number is round 2.

i'd try to change in the controldict: runTimeModifiable yes;
adJustTimeStep on;
maxCo 0.2;
maxDeltaT 1; (won't be used)

christian

Quote:

Originally Posted by Wokl (Post 471201)

Yeah i tried this as well i get the same error message and it seems like my timestep becomes really small. It feel like i tried everything. I include my model with everything except the polymesh since it's confidential. I include a picture on it.

Code:

 



Courant Number mean: 1.35547e-08 max: 0.20109

deltaT = 8.52448e-10

Time = 8.34744e-05

PIMPLE: iteration 1

DILUPBiCG:  Solving for Ux, Initial residual = 5.32808e-07, Final residual = 5.32808e-07, No Iterations 0

DILUPBiCG:  Solving for Uy, Initial residual = 1.46906e-08, Final residual = 1.46906e-08, No Iterations 0

DILUPBiCG:  Solving for Uz, Initial residual = 4.37228e-07, Final residual = 4.37228e-07, No Iterations 0

DILUPBiCG:  Solving for h, Initial residual = 1.40199e-06, Final residual = 5.26987e-15, No Iterations 1

DICPCG:  Solving for p, Initial residual = 4.51225e-08, Final residual = 4.51225e-08, No Iterations 0

DICPCG:  Solving for p, Initial residual = 4.51225e-08, Final residual = 4.51225e-08, No Iterations 0

diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0

time step continuity errors : sum local = 0.587416, global = -0.587416, cumulative = -3872.89

rho max/min : 6.5 0.5

DICPCG:  Solving for p, Initial residual = 4.51225e-08, Final residual = 4.51225e-08, No Iterations 0

DICPCG:  Solving for p, Initial residual = 4.51225e-08, Final residual = 4.51225e-08, No Iterations 0

diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0

time step continuity errors : sum local = 0.587416, global = -0.587416, cumulative = -3873.47

rho max/min : 6.5 0.5

PIMPLE: iteration 2

DILUPBiCG:  Solving for Ux, Initial residual = 5.20349e-07, Final residual = 5.20349e-07, No Iterations 0

DILUPBiCG:  Solving for Uy, Initial residual = 1.43596e-08, Final residual = 1.43596e-08, No Iterations 0

DILUPBiCG:  Solving for Uz, Initial residual = 4.33862e-07, Final residual = 4.33862e-07, No Iterations 0

DILUPBiCG:  Solving for h, Initial residual = 1.38729e-06, Final residual = 5.34883e-15, No Iterations 1

DICPCG:  Solving for p, Initial residual = 1.07862e-07, Final residual = 8.70788e-18, No Iterations 1

DICPCG:  Solving for p, Initial residual = 1.11695e-15, Final residual = 1.11695e-15, No Iterations 0

diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0

time step continuity errors : sum local = 0.587416, global = -0.587416, cumulative = -3874.06

rho max/min : 6.5 0.5

DICPCG:  Solving for p, Initial residual = 7.55031e-08, Final residual = 7.55031e-08, No Iterations 0

DICPCG:  Solving for p, Initial residual = 7.55031e-08, Final residual = 7.55031e-08, No Iterations 0

diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0

time step continuity errors : sum local = 0.587416, global = -0.587416, cumulative = -3874.65

rho max/min : 6.5 0.5

PIMPLE: not converged within 2 iterations

ExecutionTime = 922.15 s  ClockTime = 922 s

Courant Number mean: 1.34899e-08 max: 0.201615

deltaT = 8.456e-10

Time = 8.34753e-05

PIMPLE: iteration 1

DILUPBiCG:  Solving for Ux, Initial residual = 5.30154e-07, Final residual = 5.30154e-07, No Iterations 0

DILUPBiCG:  Solving for Uy, Initial residual = 1.46871e-08, Final residual = 1.46871e-08, No Iterations 0

DILUPBiCG:  Solving for Uz, Initial residual = 4.36249e-07, Final residual = 4.36249e-07, No Iterations 0

DILUPBiCG:  Solving for h, Initial residual = 1.5e-06, Final residual = 5.53155e-15, No Iterations 1

DICPCG:  Solving for p, Initial residual = 1.43943e-07, Final residual = 8.2891e-18, No Iterations 1

DICPCG:  Solving for p, Initial residual = 1.04359e-15, Final residual = 1.04359e-15, No Iterations 0

diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0

time step continuity errors : sum local = 0.587416, global = -0.587416, cumulative = -3875.24

rho max/min : 6.5 0.5

DICPCG:  Solving for p, Initial residual = 1.0076e-07, Final residual = 5.80239e-18, No Iterations 1

DICPCG:  Solving for p, Initial residual = 7.82549e-16, Final residual = 7.82549e-16, No Iterations 0

diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0

time step continuity errors : sum local = 0.587416, global = -0.587416, cumulative = -3875.82

rho max/min : 6.5 0.5

PIMPLE: iteration 2

DILUPBiCG:  Solving for Ux, Initial residual = 5.16925e-07, Final residual = 5.16925e-07, No Iterations 0

DILUPBiCG:  Solving for Uy, Initial residual = 1.41223e-08, Final residual = 1.41223e-08, No Iterations 0

DILUPBiCG:  Solving for Uz, Initial residual = 4.29323e-07, Final residual = 4.29323e-07, No Iterations 0

DILUPBiCG:  Solving for h, Initial residual = 1.49427e-06, Final residual = 4.47344e-15, No Iterations 1

DICPCG:  Solving for p, Initial residual = 5.83863e-07, Final residual = 5.98874e-18, No Iterations 1

DICPCG:  Solving for p, Initial residual = 1.34085e-15, Final residual = 1.34085e-15, No Iterations 0

diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0

time step continuity errors : sum local = 0.587416, global = -0.587416, cumulative = -3876.41

rho max/min : 6.5 0.5

DICPCG:  Solving for p, Initial residual = 4.08696e-07, Final residual = 4.19205e-18, No Iterations 1

DICPCG:  Solving for p, Initial residual = 9.95919e-16, Final residual = 9.95919e-16, No Iterations 0

diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0

time step continuity errors : sum local = 0.587416, global = -0.587416, cumulative = -3877

rho max/min : 6.5 0.5

PIMPLE: not converged within 2 iterations

ExecutionTime = 922.7 s  ClockTime = 923 s

Courant Number mean: 1.33887e-08 max: 0.201604

deltaT = 8.3886e-10

Time = 8.34761e-05

PIMPLE: iteration 1

DILUPBiCG:  Solving for Ux, Initial residual = 5.2743e-07, Final residual = 5.2743e-07, No Iterations 0

DILUPBiCG:  Solving for Uy, Initial residual = 1.46825e-08, Final residual = 1.46825e-08, No Iterations 0

DILUPBiCG:  Solving for Uz, Initial residual = 4.35096e-07, Final residual = 4.35096e-07, No Iterations 0

DILUPBiCG:  Solving for h, Initial residual = 1.65116e-06, Final residual = 6.32685e-15, No Iterations 1



 

[6] #0  Foam::error::printStack(Foam::Ostream&) in "/disk/sw/OpenFOAM/OpenFOAM-2.2.2/platforms/linux64Gcc45DPOpt/lib/libOpenFOAM.so"

[6] #1  Foam::sigFpe::sigHandler(int) in "/disk/sw/OpenFOAM/OpenFOAM-2.2.2/platforms/linux64Gcc45DPOpt/lib/libOpenFOAM.so"

[6] #2  __restore_rt at sigaction.c:0

[6] #3  Foam::hePsiThermo<Foam::psiThermo, Foam::pureMixture<Foam::sutherlandTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleEnthalpy> > > >::calculate() in "/disk/sw/OpenFOAM/OpenFOAM-2.2.2/platforms/linux64Gcc45DPOpt/lib/libfluidThermophysicalModels.so"

[6] #4  Foam::hePsiThermo<Foam::psiThermo, Foam::pureMixture<Foam::sutherlandTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleEnthalpy> > > >::correct() in "/disk/sw/OpenFOAM/OpenFOAM-2.2.2/platforms/linux64Gcc45DPOpt/lib/libfluidThermophysicalModels.so"

[6] #5  main in "/disk/sw/OpenFOAM/OpenFOAM-2.2.2/platforms/linux64Gcc45DPOpt/bin/rhoPimpleFoam"

[6] #6  __libc_start_main in "/lib64/libc.so.6"

[6] #7  _start in "/disk/sw/OpenFOAM/OpenFOAM-2.2.2/platforms/linux64Gcc45DPOpt/bin/rhoPimpleFoam"

hey

in this log your time step conituity error looks suspicious.
Can't help there, but maybe u can find something in this forum

in ur T.org file you specify 2 types of boundary conditions for the outlet. i dont know if openfoam just takes the first one or the second one.

since i cant see the model: are you setting the fields for all the domain or a part within the domain? if its the whole domain u could also set the values for internal field.

another guess: setting the boundary U outlet to pressureInletOutletVelocity. should basically do the same.

you could also try to set nOuterCorrectors for the pimple solver in the fvSolution file to 4. maybe it then converges.

did you copy the sytem folder from a tutorial? There are many div schemes listed for variables u dont calculate. But i guess this doenst matter.