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-   -   Ignition method (http://www.cfd-online.com/Forums/openfoam-solving/57973-ignition-method.html)

thumthae April 28, 2005 03:43

Hello, What is the method i
 
Hello,

What is the method in ignition process of solver XiFoam and engineFoam?

when I run a model with engineFoam and compare result with experiment, pressure from simulation result is rise before the experiment.

Does it mean ignition method in openFoam does not include ignition delay?

and What is "strength" parameter in combustionProperties ?

please give me for suggestion.

Torn

henry April 28, 2005 04:03

The best way to understand the
 
The best way to understand the ignition modelling used in XiFoam and engineFoam is to study the source code and write down the equations being used. You will find everything you need in

OpenFOAM-1.1/applications/solvers/combustion/XiFoam
OpenFOAM-1.1/applications/solvers/combustion/engineFoam
OpenFOAM-1.1/src/engine/ignition
OpenFOAM-1.1/src/engine/include/StCorr.H

piradeepan September 30, 2008 05:48

Dear All Currently I am wor
 
Dear All

Currently I am working in XiFOAM.
Please let me know, what the unit of ignition strength in combustion properties is.
Thank you
Vijay

viji February 12, 2009 04:39

hi i am from india i am new to
 
hi i am from india i am new to openfoam i am solving methane combustion problem, i am facing difficulty while assigning fields and solving please can u help me... or for reference can u send one combustion solved problem..

lfgmarc June 4, 2011 03:04

Ignition points?
 
Hi, maybe one of you can help me, I too want to know the units of the ignition strenght and how I can define more ignition points in the combustion properties ?

best regards

:confused:

FG

timaji July 29, 2011 03:47

ignition properties
 
Quote:

Originally Posted by henry (Post 200193)
The best way to understand the ignition modelling used in XiFoam and engineFoam is to study the source code and write down the equations being used.


Hi Foamers,
I have read ignite.H and found that bEqn updated to new value:

" bEqn = bEqn + Strength *cellVolume * rhou / duration " for ignite cells.

These anybodys know the perspective on physics of this formula?
Would you please help me on ignition properties e.g. strength, diameter and timing for carbon rod igniter.

camille131 June 5, 2013 13:56

Does anyone know how can I know the quantity of energy involved in the ignition in function of the parameters (strength, duration, ...) ?


I m also looking for an explaination of the meaning of strength

assuming b is a dimensionless number, I thought I could find the unity of strength from the next equation but Im not sure...

Quote:

bEqn = beqn + ((strength * cellVolume * rhou) / duration ) / (b[ignSite] + 0.001)
cellVolume [ m]
rhou [kg/m]
duration [s]
b[ignSite] and bEqn [-]
strength [?]

Then : [-] = [?] *[m]*[kg/m] / [s] --> [?] = [s/kg]

but it means nothing for me physically in this context...

for sur I am wrong but where? maybe rhou is not what I think?

Thank you for your help,
Cam


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