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-   -   Coal gasification (coalChemistryFoam) (http://www.cfd-online.com/Forums/openfoam/77877-coal-gasification-coalchemistryfoam.html)

N. A. July 6, 2010 15:24

Coal gasification (coalChemistryFoam)
 
Hi Folks,

I am trying to use coalChemistryFoam to simulate coal gasification. I am using coal particles mixed with steam coming out of inlet of a gasifier. However I get some instability when solving for chemistry indicating that the temperature is out of bounds when slving for chemistry (see error below). My questions are:

1. has anyone used coalChemistryFoam to simulate coal-gasification.
2. if yes, can you share the sample input files and set-up files.

Thanks,
Nir

-------------------------
Error
-------------------------
Solving chemistry
attempt to use janafThermo<equationOfState> out of temperature range 0 -> 5000; T = -172.4576252
attempt to use janafThermo<equationOfState> out of temperature range 0 -> 5000; T = -172.4576252
attempt to use janafThermo<equationOfState> out of temperature range 0 -> 5000; T = -168.8897125
attempt to use janafThermo<equationOfState> out of temperature range 0 -> 5000; T = -168.8897125
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for Ux, Initial residual = 0.06252264858, Final residual = 2.128743217e-07, No Iterations 3
DILUPBiCG: Solving for Uy, Initial residual = 0.05006504269, Final residual = 1.698478568e-07, No Iterations 3
DILUPBiCG: Solving for Uz, Initial residual = 0.04849053656, Final residual = 1.647714921e-07, No Iterations 3
DILUPBiCG: Solving for O2, Initial residual = 9.278860932e-06, Final residual = 5.681887612e-08, No Iterations 1
DILUPBiCG: Solving for CH4, Initial residual = 1.523074818e-06, Final residual = 1.138947373e-08, No Iterations 1
DILUPBiCG: Solving for H2, Initial residual = 1.53011947e-06, Final residual = 1.144182535e-08, No Iterations 1
DILUPBiCG: Solving for CO2, Initial residual = 1.523069754e-06, Final residual = 1.138943648e-08, No Iterations 1
DILUPBiCG: Solving for H2O, Initial residual = 1.242080567e-06, Final residual = 7.387563002e-09, No Iterations 1
DILUPBiCG: Solving for h, Initial residual = 7.844066942e-07, Final residual = 7.844066942e-07, No Iterations 0
attempt to use janafThermo<equationOfState> out of temperature range 0 -> 5000; T = -165.0947803
attempt to use janafThermo<equationOfState> out of temperature range 0 -> 5000; T = -165.0947803
attempt to use janafThermo<equationOfState> out of temperature range 0 -> 5000; T = -162.1038572
attempt to use janafThermo<equationOfState> out of temperature range 0 -> 5000; T = -162.1038572
DICPCG: Solving for G, Initial residual = 7.414788851e-06, Final residual = 7.414788851e-06, No Iterations 0
DILUPBiCG: Solving for p, Initial residual = 0.06213669809, Final residual = 2.115563004e-11, No Iterations 4
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 4.5111303e-14, global = -1.98763565e-14, cumulative = -6.750422694e-11
DILUPBiCG: Solving for p, Initial residual = 7.208921875e-09, Final residual = 7.208921875e-09, No Iterations 0
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 9.36121857e-12, global = -1.98763636e-14, cumulative = -6.75241033e-11
T gas min/max = 200, 450
DILUPBiCG: Solving for k, Initial residual = 0.962630372, Final residual = 3.331572521e-09, No Iterations 5
ExecutionTime = 2.91 s ClockTime = 3 s

leosding July 7, 2010 03:42

na,
maybe you can refer the post "Patches for OpenFOAM 1.7 on MacOS X"

maybe a bug, or the problems of configurations.

Leo

yingkun June 14, 2011 00:20

I have the same problem,have you solved it?

gregor June 14, 2011 04:49

Hi,

an easy way would be using openFOAM 1.7.1 (which solves equations for hs instead of h). At least for me it avoided some janaF errors.

gregor

yingkun June 14, 2011 05:43

hi,
I do use OF1.7.1, and it shows the problem

gregor June 14, 2011 05:58

ok sorry the inital poster did not but it is an old post anyway.
janaF errors can have numerous reasons (boundary conditons, models etc.) and without posting any details about your case there is no way to find a solution.

yingkun June 14, 2011 06:28

2 Attachment(s)
Quote:

Originally Posted by gregor (Post 311924)
ok sorry the inital poster did not but it is an old post anyway.
janaF errors can have numerous reasons (boundary conditons, models etc.) and without posting any details about your case there is no way to find a solution.

hi,
the model is just as the tutorial case simplifiedSiwek, I just change the mesh and boundary conditions and relational files in constant, my case has two inlets(inlet1 jets coal and primary air at 300K,inlet2 jets preheated air at 1500K):
Attachment 8036

the BC like follows:
Attachment 8034
or can you give me your QQ or sth (mine :549844146)and then I will show you more detail informations

gregor June 15, 2011 04:35

Hi,

first of all i have experienced difficulties when using "mixed" boundary conditions for different species. You have a zeroGradient condition for H2,CH4,CO at the inlets and fixedValue for the other species. So use fixedValue = 0.0 for H2 as well.
What time scheme are you using ? I had trouble when using CN with a high explicit ratio . And you could try to switch of radiation,particles etc. just to eliminate possibilities.


gregor

yingkun June 15, 2011 05:06

1 Attachment(s)
Quote:

Originally Posted by gregor (Post 312064)
Hi,

first of all i have experienced difficulties when using "mixed" boundary conditions for different species. You have a zeroGradient condition for H2,CH4,CO at the inlets and fixedValue for the other species. So use fixedValue = 0.0 for H2 as well.
What time scheme are you using ? I had trouble when using CN with a high explicit ratio . And you could try to switch of radiation,particles etc. just to eliminate possibilities.


gregor

yes,I do change the radiation model,time step and something, but do not work.The paticles--I don't really know where and how to change,the only correlative files are the constant\coalcloud1properties and coalcloud1positions which I don't know how to set
Attachment 8039

gregor June 15, 2011 06:01

you can deactivate the particles in constant\coalcloud1properties by setting active to false. but try to change your boundary conditions first.

gregor

niqbal August 4, 2011 06:28

yingkun
 
Hi,
I enter in the thread as I am also simulating the similar case, but with some variations, has you solved your problem or not ? I have changed this case to a cylindrical domain, where I have modified the coalCloud by increasing the number of particles and and some other details, it is working fine, but then I changed the boundray condition (inlet U) to some flow rate option, it is still working but it is taking too long. If the thread is still active we can share some of our experience.
Cheers,
Naveed

yingkun August 8, 2011 23:10

hi
I came back home those days,that why I reply so late.
I change the geometry and boundary conditions,and eject coal horizontally from the left face,now I meet some problems,it just can calculates a short time,may be we can discuss it.


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