CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

greyMeanAbsorptionEmission

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 20, 2010, 07:50
Default greyMeanAbsorptionEmission
  #1
New Member
 
magnus
Join Date: Apr 2009
Posts: 7
Rep Power: 17
mange is on a distinguished road
Hi,

I have added the radiation module into reactingFoam and it seems to work fine.
My question now is how to use "greyMeanAbsorptionEmission" so that I can have absorption and emmission coefficients as a function of , say, CO2 massfraction.
As I understand the calculated species massfraction will be used since i am solving for CO2. Therfore I can give polynomial coefficients in a greyMeanAbsorptionEmissionCoeffs sub dictionary.
There seems also to be an option of defining the coefficients in a lookuptable . I do so far not have intentions of using this table but it seems that it must exist in order to use the class. The table should be located under constant/ and if it does not exist the solver exits with a fatal error
I have studied the source for the class but I run into trouble with the interpolationLookUpTable and cannot figure out what format the input file should be.

I think it should be of class dictionary, and it has to contain the keywords fields, output and value. But everything I try just fails

Anyone has an idea about this??
mange is offline   Reply With Quote

Old   January 21, 2010, 04:19
Default
  #2
New Member
 
magnus
Join Date: Apr 2009
Posts: 7
Rep Power: 17
mange is on a distinguished road
By the way I am using 1.6.x .

Any suggestions or hints would be highly welcomed.
Did anyone use this model before?
mange is offline   Reply With Quote

Old   January 26, 2010, 09:27
Default
  #3
New Member
 
magnus
Join Date: Apr 2009
Posts: 7
Rep Power: 17
mange is on a distinguished road
Hi again,

I managed to find a working format, which looks like this:

fields
1
(
{
N 1;
max 1.0;
min 0.0;
name apa;
}

)
;
output
1
(
{
name apa;
}
)
;
values
2
(
(0 0.0)
(1 0.0)
)
;

I am still very confused of what this does. But I am solving for the species of interest so I hope it does not influence anyhow. I also had to create a volScalarField called "ft" for it to work and "ft" needs to be registered with the other species and appearently solved for as well. well I just put it to zero in the entire field.

I now managed to get the absorptioncoefficient as a function of CO2. But I do not know if I can trust the results since I have the feeling that i have misunderstood something important here.

Could anyone shed some lights on this?
mange is offline   Reply With Quote

Old   September 11, 2010, 21:26
Default
  #4
New Member
 
Sina
Join Date: May 2010
Posts: 7
Rep Power: 16
shajitah is on a distinguished road
Hi Magnus,

I have encountered the same problem right now. I was wondering if you so far has fixed the problem, and give some info of how to define the SpeciesTable dictionary. By the way, I've also sent you a private message with more details.

Thanks
Sina
shajitah is offline   Reply With Quote

Old   September 15, 2010, 17:47
Default
  #5
Member
 
Paulo Bufacchi
Join Date: Jun 2010
Posts: 50
Rep Power: 16
Bufacchi is on a distinguished road
Guys,

Please take a look at fireFoam. It uses exactly what you are looking for, although there is no white paper explaining the code.

Regards,

Paulo
Bufacchi is offline   Reply With Quote

Old   May 2, 2012, 09:49
Default
  #6
New Member
 
Join Date: Feb 2012
Posts: 25
Rep Power: 14
Marshak is on a distinguished road
Can anyone explain the code for 'SpeciesTable' in case of grey mean absorption model used ?
Marshak is offline   Reply With Quote

Reply

Tags
greymeanabsorption, interpolationlookup, radiation, table


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 10:51.