I am a beginner of OF,and now try to simulate SI engine by using engineFoam.
I want to change equivalenceRatio from 1.0 to 0.8.
And,I changed equivalenceRatioin in "constant/combustionProperties" file.
Could I really change ratio?
I need to change another property?

please help me..

[lucchini]

Hi Noriaki,
to change the equivalence ratio you don't have to change it in the constant/thermophysicalProperties, but you have to change the value of ft in the ./-180 directory. ft is the fuel mass fraction, i.e. fuel/(air+fuel), which you can easily relate with the air/fuel ratio and/or the equivalence ratio.
Bye
Tommaso

Thank you very much.
Noriaki.

Thank you very much.
TO Tommaso.

I want to change compression ratio.
And I changed stroke and clearance value.
But I could not change the ratio.
I need to change another properties?
Please help me.

[kukikano]

Hi Noriaki,

How do you check the compression ratio? engineCompRatio? Changing the stroke should be enough. Try (in the directory where your case is):

engineCompRatio . case

(where 'case' would be kivaTest if you run the tutorial)
-- change the stroke in case/constant/engineGeometry
-- run engineCompRatio again and see what happens (something should happen)

You can see how the piston motion is calculated in /home/user/OpenFOAM/OpenFOAM-1.3/src/engine/engineTime/engineTime.C.

Rikard

Thank you Rikard,
I will try it.

Thank you Rikard,
I will try it.

Hi Tonnaso,
I could not open file in the ./-180 directory.
I do not know the reason.
Please tell me.

Hi Everyone.

In engineFoam, we can get "log_summery.-15" file after calculation.
It seems that mean pressure and mean temperature is written in it, but I don't know how calculate mean value.

Weighted mean value or something??

Please someone help me.

Thanks.

Atsushi

[kukikano]

Hi Atsushi,

The code that writes to the logSummary file is found in /home/user/OpenFOAM/OpenFOAM-1.3/applications/solvers/combustion /engineFoam/logSummary.H

The values written to the file are volume-weighted averages, calculated with

field.weightedAverage(mesh.V()).value()

or

sum(field*mesh.V())/sum(mesh.V())

Rikard

Thank you for your reply, Rikard.

Does it mean that
"add temperature of all cell" / "add volume of all cell" ??

Atsushi

I am the japanese college student. Please teach me.
I run the engineFoam now.
I want to put chemistryModel in engineFoam.
should I change engineFoam.C or another files?
please tell me how to this definitely.
thanks..

[lucchini]

Hi,
what do you want to simulate with engineFoam and chemistryModel?
regards
tommaso

[lucchini]

Hi,
what do you want to simulate with engineFoam and chemistryModel?
regards
tommaso

Hi,
By running the engineFoam,I want to see the CO2,N2,O2 distribution such as the result of dieselFoam.

I try to model premix combustion in SI engine. I use kivaTest in the tutorial.
Xi=∑/∑0?
What is Xi?
Help me please.

[arkangel]

Hi in a domain of the scale found in pitzDaily, What are the parameters to be chosen in ignites sites in order to ensure a complete combustion.

All is running stable and then an error
FOAM FATAL ERROR : attempt to use janafThermo<equationofstate> out of temperature range 200 -> 6000;

I saw a lot of people having this error , so far noone has a satisfactory answer

the Courant number is in the range
but b min(b) grows up to O(10^-5) with a combustion progress of 50 or 60 %


any idea to bound b or any possible reason for such error

[tsencic]

I am using dieselEngineFoam.

How can I display the rate of heat release?

What are the fields:
dQ
phi
kappa
meshPhi
H

in the time directories?

Hello everyone,

What is the difference between 'engineFoam' and 'coldEngineFoam'?

I just want to know what kind of simulations I can do in 'coldEngineFoam'.

Any help will be welcome.
Thanks.

Atsu