[henry]

The specified ignition location is indeed outside the domain, try changing it to

location (0.03 0 0.091);

[thumthae]

Henry

I just finished run engineFoam with spark location at center 0.0, 0.0, 0.092, combustion exist. However when combustion progress reach about 6.7 % it error.

like here....

Combustion progress = 6.7208%
BICCG: Solving for hu, Initial residual = 0.00182041, Final residual = 1.09263e-06, No Iterations 1
BICCG: Solving for h, Initial residual = 0.00200048, Final residual = 1.02023e-06, No Iterations 1


--> FOAM FATAL ERROR : attempt to use janafThermo<equationofstate> out of temperature range 298.15 -> 5000; T = 296.354

Function: janafThermo<equationofstate>::checkT(const scalar T) const
in file: /home/dm2/henry/OpenFOAM/OpenFOAM-1.1/src/thermophysicalModels/specie/lnInclude/ janafThermoI.H at line: 73.

FOAM aborting

Aborted

.............................................

It strange at line

file: /home/dm2/henry/OpenFOAM/OpenFOAM-1.1/src/thermophysicalModels/specie/lnInclude/ janafThermoI.H at line: 73.

I don't have this folder(/home/dm2/henry/), why it show in error message.

Thank.
Torn

[henry]

I think the difference in behaviour between Foam2.2 and OpenFOAM is in the heat-transfer boundary condition. I can get the kivaTest case to run fine with adiabatic walls but not with fixed temperatures wall. I will investigate further but in the meantime try running adiabatic.

[henry]

I have found the problem with the heat transfer, it does not relate to the temperature field T but to the unburnt gas temperature Tu so the problem only occurs for codes using the hhu* thermodynamics packages like Xoodles, XiFoam and engineFoam and only for cases with fixed temperature walls. I will include the corrected thermodynamics package in the 1.1.1 release, in the meantime if you are running these codes I suggest you use adiabatic walls.

[thumthae]

Henry, Thank you for the investigation.

With adiabatic wall the solution quite over predicted. So I change to wallFunction b.c. type,which it not fixed temperature and I got resonable results.

However, I'm not clear what the physical of wallFunction b.c. condition.

What differences of wallFunction compare with wallFixedTemp and wallAdiabatic.

please suggest.

Torn

[henry]

Have a look at the boundary conditions each of these options sets for the fields and you will see the difference. You can reconfigure FoamX to give a different set of boundary conditions for your cases if you need to or edit the fields directly.

[thumthae]

Hi Henry

After I run engineFoam, I got some strange with the combustion progress is over 100% and b value is negative.

Is it bug of the solver?

[henry]

This is not a bug in the solver it is unboundedness associated with your choice of discretisation schemes time-step etc. How negative is b? What schemes have you tried? What coefficient are you using for the schemes you have tried?

[thumthae]

Henry,
All schemes are defult scheme of engineFoam. I got b=-0.03

with backward-different scheme I got b=-0.27

However I think it not concern with result because the combustion finished since 100% progress(b=0)

Torn

[henry]

You should not rely on the defaults and choose schemes appropriate for your case. If you are not sure what is appropriate you should try out combinations until you get the best balance between accuracy, boundedness, stability and efficiency, this is standard practice in CFD.

[mattos]

Hi Henry

In the message of Feb/04-2005 you give us an electronic address to access your report and article abstract (monet.me.ic.ac.uk) . But I had not success to acess it, because it appear for me that it is unknown host. Is that address unavailable now? What can I do to obtain these docs?

And congratulations for the initiative to left OpenFoam as open source for CFD community.

Tanks you in advance for your help

Wladimyr

[henry]

Unfortunately due to errors in the administrators of monet.me.ic.ac.uk the web-site is down/not accessible and we will have to find another home for these documents. Do you know which ones you would like to have?

[mattos]

Hi Henry

Fisrt, I would like to obtain these two references that you wrote at Feb/04-2005 which are related with the combustion models implemented in OpenFOam.

Second, if you may list all references which are related with the combustion models implemented in the OpenFoam it can help us very much. Are these references available for general public? I would like to suggest to include the references that the solvers are based as comments in the source code of these ones (if it is not alread donne!).
I would like to use the Openfoam in our researches of gas turbine combustion chamber and rocket engines.

Once more, tank you in advance for your help.

Wladimyr

[henry]

We are planning to create a page on the web-site from which you will be able to download all our papers and reports but I am not sure when it will be ready. Recently I started pulling together all the reports I have written in the past on my combustion modelling into a single consistent report, it's not finished but at least it includes everything I have written so far on my model and I will Email you what I have done so far.

Currently the only premixed/partially premixed model released with OpenFOAM is my own model but it is easy to implement most other models like presumed-PDF, eddy-break-up etc. etc. The only model included to Diesel combution is the EDC model from the guys at Chalmers -- contact them for more info.

[lucchini]

I have a copy of the TF9307 report. If you are interested in send me an e-mail and I can send it to you.
ciao
tommaso

[thumthae]

Hi Wladimyr,

I have a copy of "Application of a Flame-Wrinkling LES Combustion Model to a Turbulent Mixing Layer" if you want I can sent it to you

Tommaso
Do you also run the combustion solver. May be we can exchange an experience.

[mattos]

Hi Tommaso and Chalothon

First of all, I wish send many tanks fou your promptness offer. Please, could you send me these reports to me? I will be very glade. You can mail me to gmail addres: wladimyrmd AT gmail dot com, because it is wider then my terra accout. But if it is not so big, you can send me to terra account anyway. The addres is: wladimyrmd AT terra dot com dot br.

I think that soon I will participate in the exchange of experience discussion group. I would like to test OpenFOam in the same test case that I considered in my PhD. Thesis: turbulent reactive wake of a bluf body.

Many tanks in advance

Wladimyr Dourado

[seang]

hiya Wladimyr

just wondering, are you looking at the Sandia bluff body flames (non-premixed) for your phd?

Tek Seang

[mattos]

Hi Tek Seang

I really concluded my PhD one and half year ago. I used data of LCD/CNRS at Poitiers premixed test bench to validate my code. It is a rectangular cross section channel with bluff body inside where blocking ration variates since 33% up to 50%. I really tested only one geometry, one blocking ration and one flow mass. I need test my code for others configurations which experimental data are available.

Did I answer you?

Wladimyr Mattos C. Dourado

[adorean]

Hello,

I would very much appreciate some guidelines for using 'dieselEngineFoam'.

Is it OK to define the piston, liner and cylinderhead temp. b.c. as fixedValue?

And how is that light speed-like value of "Average Velocity for injector 0: 5.63034e+06 m/s, injection pressure = 1200 bar" calculated?
Does this need to be calculated, even if injection doesn't exist at that time?

For a calculation starting at -180 CAD and ending at -10 CAD, the injection beginning at -4.4 CAD I always get divergence quite soon (-170 CAD for ex. or sooner), because of a high Courant number.
Which is the best way of keeping the Courant number low?

Or, maybe my case setup is wrong.
If anyone has experience with dieselEngineFoam, please help me setup correctly a case: the 'time' directory and the 'system' directory are those that I'm not sure that are OK.

Thanks!

Ervin