I have include temperature field in IcoFoam and I have run it after a while it is stopping. Diameter of pipe is 0.001m and length is 1m, velocity is 0.212 m/s. it gives me this message
Time = 0.085

Courant Number mean: 5.92365e+55 max: 2.22812e+59
DILUPBiCG: Solving for Ux, Initial residual = 0.999827, Final residual = 28.78, No Iterations 1001
DILUPBiCG: Solving for Uy, Initial residual = 0.999891, Final residual = 13.7978, No Iterations 1001
DILUPBiCG: Solving for Uz, Initial residual = 0.993418, Final residual = 5.55113, No Iterations 1001
DICPCG: Solving for p, Initial residual = 1, Final residual = 0.728859, No Iterations 1001
time step continuity errors : sum local = 1.93343e+63, global = -4.09326e+57, cumulative = -4.09326e+57
DICPCG: Solving for p, Initial residual = 0.978532, Final residual = 18.7317, No Iterations 1001
time step continuity errors : sum local = 1.56696e+66, global = 1.27684e+62, cumulative = 1.2768e+62
#0 Foam::error::printStack(Foam:stream&) in "/home/rkahraman/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/home/rkahraman/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libOpenFOAM.so"
#2 ?? in "/lib64/libc.so.6"
#3 Foam::PBiCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/home/rkahraman/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libOpenFOAM.so"
#4 Foam::fvMatrix<double>::solve(Foam::Istream&) in "/home/rkahraman/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libfiniteVolume.so"
#5 main in "/home/rkahraman/OpenFOAM/OpenFOAM-1.5/applications/bin/linux64GccDPOpt/my_icoFo am"
#6 __libc_start_main in "/lib64/libc.so.6"
#7 Foam::regIOobject::readIfModified() in "/home/rkahraman/OpenFOAM/OpenFOAM-1.5/applications/bin/linux64GccDPOpt/my_icoFo am"
Gleitkomma-Ausnahme

thanks for suggestion

Emo

Hello Sebastian,

it gives the same error like previous one with solver rhoPimpleFoam.

it is stopping..What is wrong can you help me?

thanks in advance

Emo

Hello Sebastian again,

I have run my case with solver rhoPimpleFoam.
it gives me the following problem

Starting time loop

Courant Number mean: 0 max: -0
Time = 1

#0 Foam::error::printStack(Foam:stream&) in "/home/rkahraman/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/home/rkahraman/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libOpenFOAM.so"
#2 ?? in "/lib64/libc.so.6"
#3 void Foam::fvc::surfaceIntegrate<foam::vector<double> >(Foam::Field<foam::vector<double> >&, Foam::GeometricField<foam::vector<double>, Foam::fvsPatchField, Foam::surfaceMesh> const&) in "/home/rkahraman/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libfiniteVolume.so"
#4 Foam::tmp<foam::geometricfield<foam::vector<double >, Foam::fvPatchField, Foam::volMesh> > Foam::fvc::surfaceIntegrate<foam::vector<double> >(Foam::GeometricField<foam::vector<double>, Foam::fvsPatchField, Foam::surfaceMesh> const&) in "/home/rkahraman/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libfiniteVolume.so"
#5 Foam::tmp<foam::geometricfield<foam::vector<double >, Foam::fvPatchField, Foam::volMesh> > Foam::fvc::div<foam::vector<double> >(Foam::GeometricField<foam::vector<double>, Foam::fvsPatchField, Foam::surfaceMesh> const&) in "/home/rkahraman/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libfiniteVolume.so"
#6 Foam::tmp<foam::geometricfield<foam::vector<double >, Foam::fvPatchField, Foam::volMesh> > Foam::fvc::div<foam::vector<double> >(Foam::tmp<foam::geometricfield<foam::vector<doub le>, Foam::fvsPatchField, Foam::surfaceMesh> > const&) in "/home/rkahraman/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libfiniteVolume.so"
#7 Foam::fv::gaussLaplacianScheme<foam::vector<double >, double>::fvmLaplacian(Foam::GeometricField<double, > const&, Foam::GeometricField<foam::vector<double>, Foam::fvPatchField, Foam::volMesh>&) in "/home/rkahraman/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libfiniteVolume.so"
#8 Foam::fv::laplacianScheme<foam::vector<double>, double>::fvmLaplacian(Foam::GeometricField<double, > const&, Foam::GeometricField<foam::vector<double>, Foam::fvPatchField, Foam::volMesh>&) in "/home/rkahraman/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libfiniteVolume.so"
#9 Foam::tmp<foam::fvmatrix<foam::vector<double> > > Foam::fvm::laplacian<foam::vector<double>, double>(Foam::GeometricField<double,> const&, Foam::GeometricField<foam::vector<double>, Foam::fvPatchField, Foam::volMesh>&, Foam::word const&) in "/home/rkahraman/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libcompressibleRASMod els.so"
#10 Foam::tmp<foam::fvmatrix<foam::vector<double> > > Foam::fvm::laplacian<foam::vector<double>, double>(Foam::GeometricField<double,> const&, Foam::GeometricField<foam::vector<double>, Foam::fvPatchField, Foam::volMesh>&) in "/home/rkahraman/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libcompressibleRASMod els.so"
#11 Foam::compressible::RASModels::kEpsilon::divDevRho Reff(Foam::GeometricField<foam ::vector<double>, Foam::fvPatchField, Foam::volMesh>&) const in "/home/rkahraman/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libcompressibleRASMod els.so"
#12 main in "/home/rkahraman/OpenFOAM/rkahraman-1.5/applications/bin/linux64GccDPOpt/rhoPimp leFoam"
#13 __libc_start_main in "/lib64/libc.so.6"
#14 Foam::regIOobject::readIfModified() in "/home/rkahraman/OpenFOAM/rkahraman-1.5/applications/bin/linux64GccDPOpt/rhoPimp leFoam"
Gleitkomma-Ausnahme

can someone help me?
best regards

Emo

[cedric_duprat]

Hi Emilian

about your 03:29 post, your mistake occure before, because, this time step show a time step continuity error of 1.56696e+66 which is ..... wrong.

about your last post now, I don't know the solution but, keep in mind that if in the message there is something with Foam::sigFpe it just mean, usualy that you divide by 0.

So, ..... check your boundary conditions (initial values) and you will solve your problem by yourself

hope it helps,

Cedric

juuppiii...I have done...thanks very much Cedric

[cedric_duprat]

be carefull, It's the begining of a new world now !!
:-)

[sebastian_vogl]

Hello Emilian,

in addition to Cedric's post I would also recommend that you take care of the Courant number which you specify in the <case>/system/condrolDict dictionary. In your case (of your post on 3:29) it is 2.22812e+59. It shoud, however be between 0 and 1: 0<Courant<1. A small value like 0.1 means good stability and a higer value, e.g. 0.5, is good for a shorter simulation time. But it must never be 1 or higher. Even values like 0.8 can be to high. If you want to be on the safe side, I guess Co=0.1 is a good value. If the controlDict file allows it than use the item "addjusableRunTime". It varies the simulation time step so that your speciefied Courant number is guaranteed.
The residuals of your variables, pressure, velocity is to high. Make sure that the final residuals are in the order of 1e-6 or even smaller (1e-8, 1e-9). You can specify the tolerance in: <case>/system/fvSolution. There is some good information about it in the User Guide chapter 4.4/4.5.

Referring to your post of 6:38:
A possible mistake (I'm not sure) is, that rhoPimpleFoam is a solver for turbulent flows. So if your flow is laminar you will have to go into the <case>/constant/RASPropertis file and switch of turbulence. As turbulence model you take laminar. This is a dummy-turbulence model. Maybe that could help you.

Best regards,
Sebastian

Thanks Sebastian it is working well...

best regards

EMO

[lara_areis]

Dear all

I am quite new in CFD and OpenFoam.
I am trying to simulate de dispersion of gas pollutants in the the atmosphere using dieselFoam, with chemistry off.
I used the ammonia case that Niklas Nordin post on the forum as a build up point. I have changed the mesh to a much simpler case in witch the inlet is the whole left wall. It seems as though I have been having some problem with the injectorProperties. What I wanted to know to be able to continue is what is really the function of the injectorProperties? Do these properties control the entrance of the pollutants at the inlet? or can I simply define a velocity boundary condition and a concentration at the inlet, and not use the injectorProperties?

Thank you in advance
Best regards

Lara

[lara_areis]

Dear all

I am quite new in CFD and OpenFoam.
I am trying to simulate de dispersion of gas pollutants in the the atmosphere using dieselFoam, with chemistry off.
I used the ammonia case that Niklas Nordin post on the forum as a build up point. I have changed the mesh to a much simpler case in witch the inlet is the whole left wall. It seems as though I have been having some problem with the injectorProperties. What I wanted to know to be able to continue is what is really the function of the injectorProperties? Do these properties control the entrance of the pollutants at the inlet? or can I simply define a velocity boundary condition and a concentration at the inlet, and not use the injectorProperties?

Thank you in advance
Best regards

Lara

[lara_areis]

hello again

I am running the ammonia case from Niklas Nordin and I have changed only the mesh and the controlDict.
At time 2.466568e+04 stops here:

DILUPBiCG: Solving for h, Initial residual = 0.000156685, Final residual = 5.38316e-10, No Iterations 2

and it keeps giving me this error message

attempt to use janafThermo<equationofstate> out of temperature range 200 -> 5000; T = 199.974#0 Foam::error::printStack(Foam:stream&) in "/home/aleluia/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libOpenFOAM.so"
#1 Foam::error::abort() in "/home/aleluia/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libOpenFOAM.so"
#2 Foam::specieThermo<foam::janafthermo<foam::perfect gas> >::H(double) const in "/home/aleluia/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libcombustionThermophysic alModels.so"
#3 Foam::hMixtureThermo<foam::reactingmixture>::calcu late() in "/home/aleluia/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libcombustionThermophysic alModels.so"
#4 Foam::hMixtureThermo<foam::reactingmixture>::corre ct() in "/home/aleluia/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libcombustionThermophysic alModels.so"
#5 main in "/home/aleluia/OpenFOAM/OpenFOAM-1.5/applications/bin/linuxGccDPOpt/dieselFoam"
#6 __libc_start_main in "/lib/tls/i686/cmov/libc.so.6"
#7 Foam::regIOobject::writeObject(Foam::IOstream::str eamFormat, Foam::IOstream::versionNumber, Foam::IOstream::compressionType) const in "/home/aleluia/OpenFOAM/OpenFOAM-1.5/applications/bin/linuxGccDPOpt/dieselFoam"


From function janafThermo<equationofstate>::checkT(const scalar T) const
in file /home/dm2/henry/OpenFOAM/OpenFOAM-1.5/src/thermophysicalModels/specie/lnInclude/ janafThermoI.H at line 70.

FOAM aborting

Aborted


can some one help me?

regards

Lara

[sebastian_vogl]

Hi Lara,

the dieselFoam solver is made to simulate spray combustion. So somehow the liquid fuel must enter the domain. Like in a diesel engine, the fuel is injected by an injector which has a certain spray characteristic. When you look in the injectorProperties file in the constant folder, you can see that the injector needs to know how much fuel (mass) you want to inject, which diameter the droplets are supposed to have, etc. Depending on the injector type you choose you can also specify the velocity of the parcels, which represent your spray, when injected or you can specify the pressure of injection. So, you supply all data, which are necessary to define this injector.
When you intend to simulate the dispersion of liquid pollutants, that can be represented by spherically droplets, in air, you can define an injector, which introduces the pollutants into the domain according to your demands.
For simulating the dispersion of gas pollutants like N02 of CO in air, the dieselFoam solver is originally not made for, as it is an two phase flow solver with additional combustion.
However dieselFoam can handle different (gas) species in the following way:
When you look into the 0 folder, you can see files for oxygen, nitrogen an also an Ydefault file. These all define the initial conditions for gas species. So the oxygen and nitrogen files specify the composition of your air, as air consists of both gases. The values supplied there are written as mass fractions and not concentrations. That means you have mass of species A divided through the total mass in the finite volume.
The Ydefault file specifies the mass fractions for all other gases which are written in your therm.dat and chem.inp file of chemkin folder. For a special species you need to define your own file in this folder. For example if you want to simulate the distribution of NO2 in air you create yn NO2 file in the 0 folder and define the mass fractions at the inner field and boundary conditions there. As dieselFoam has a species transport equation, you can then simulate its distribution. You must make sure that this species is defined in the therm.dat file (maybe also in the chem.inp file). I don't know whether you need to incorporate your selfmade gas species file somewhere in the code.
Niklas Nordin answered to a similar post about creating a gas species file. A person wanted to specify the distribution of CH4 in the domain. Unfortunately I can't find the post on my own in a short time. So you may search for it.
For more details about the dieselFoam case setup you can look at the Wiki-page made by Niklas Nordin, which lists all attributes of the solver you can specify. There is also an description of the injectorProperties-file.

http://openfoamwiki.net/index.php/Contrib_dieselFoam


I hope, my post helped you a little bit.

Best regards,
Sebastian

[lara_areis]

Thank you sebastian

I have specified the injection time for a time after my endTime. But I am now getting the error that I have posted before.
I'll use your hint to look for the post about distribution of CH4.

Thank you very much

Lara

[sebastian_vogl]

Hi Lara,

referring to your last post.

As you can see in the line:

attempt to use janafThermo<equationofstate> out of temperature range 200 -> 5000; T = 199.974#0

its a little bit cold within your domain.
The properties of your gas species is represented by functions which are based on the coefficients, which are written within your therm.dat file. When you open this file, you will see the collection of numbers for each species. You can see from your error message that the functions for one ore more species are only valid within the given temperature range:
200 -> 5000K

So as for an colder environment the coefficients for this functions are not valid, your simulation crashed. You should first restart the simulation from the last written time step and find out whether this error occurs again, then do the post processing and find out why it is so cold in your domain and change the setting so that the temperature doesn't decrease so much.

Best regards,
Sebastian

[lara_areis]

Hi Sebastian

Thank you very much for the answer.

I have noticed that Temperature was falling out of the given range .. My question is then:
Should OpenFoam be using the therm.dat information if chemistry is switch off?
Because in my understating, if species are set to not react... how can temperature fall to ~199K?

Thank you very much

regards

Lara

[lara_areis]

Hi Sebastian

Thank you very much for the answer.

I have noticed that Temperature was falling out of the given range .. My question is then:
Should OpenFoam be using the therm.dat information if chemistry is switch off?
Because in my understating, if species are set to not react... how can temperature fall to ~199K?

Thank you very much

regards

Lara

[sebastian_vogl]

Hi Lara,

to be more exactly, the coefficients within the therm.dat file are used to build up a function which describes the heat capacity of every species as a function of temperature. So the heat capacity varies when the temperature changes. When you want to see how this function looks like, go into the OpenFOAM source-folder and search for a file with a name like "janafThermo.C". Or may be the function is written within the header file, I don't know anymore. However it is an polynomial function which looks for the right coefficients in the therm.dat file and constructs an polynomial function out of these coefficients and then this function describes the heat capacity of this species, where the coefficients were taken from, as a function of time. Also "oxygen" and "nitrogen", which are the main components of "air", have got their coefficients written within this file.
I don't know exactly how and where the temperature of a cell is calculated in dieselFoam for the case that there is no reaction. If there is an reaction the so called "adiabatic flame temperature" is calculated, which is the maximaum temperature that can occur during a reaction step. But I guess that somewhere the mixture enthalpy of all species in one cell is divided through the heat capacity, but I don't know. Better you send an E-mail to Mr Nordin and ask him (and tell me what he said about it). He is always very nice and will surely write back. I have written him so many times and he has always answered kindly and patiently to me.
But when forgetting about implementation and just looking on your problem from a physical point of view:
When the velocity within your domain increases the static pressure decreases and then also the static temperature, or just temperature, decreases. So you may have an unrealistic high velocity somewhere in the domain, although I have to admit that your temperature is extremely low. This could be an explanation. What you could do, is to set adjustableRunTime in the controlDict in your system folder to "yes" and then specify a Courant number Co of e.g. 0.1. The simulation time step will then be determined by the fluid velocity, the mesh size and the Courant number you set. During the simulation process you can look in your log-file and have a look on the simulation time. For the case that all of your cells have the same size, the simulation time is only determined by the flow velocity. If the simulation step decreases continuously, then the flow velocity will increase. If it is too high, the temperature drop may be high, too.
A further reason for your problem could be that you set a wrong (to low) initial temperature for your flow field. This may sound silly to you. But sometimes mistakes one makes are so simple that one misses it because of that.
Maybe it is just a numerical error and if you start simulation again, it doesn't happen again. I can recall having had such a situation on my own. If my suggestions don't help, you should definitely advise Mr Nordin, as he wrote the code, or ask some of the other OpenFOAM experts, as my knowledge is not very good, yet.

Best regards,
Sebastian

[lara_areis]

Thank you once again sebastian.

I'll follow your advise ;)

regards

Lara

[haghajani]

Dear all,

Please let me know, How does dieselFoam work?

Is it possible to study a LIQUID JET (Liquid Hydrogen) coming out from a simple orifice (d = 1 cm); which its physics involve atomization/spray seconds after spill and vaporization very quickly in atmosphere (flash vaporization) due to its very low boiling point. (droplets will form in atomsphere after coming out from orifice)

I run the aachenbomb case with following settings in "injectorProperties" to investigate how the C7H16 Liquid comes out,
injectorType unitInjector;
diameter 0.005;
cd 1;
mass 6e-4;
temperature 320;
nParcels 10000;
massFlowRateProfile
(
(0 0.12)
(0.005 0.12)
);

Results in paraFoam do not show any LIQUID JET or liquid particle in system? (How can i track/visualize them?)

In case this is not the proper solver, which other ones do you suggest?
Best,
Hamed