[niklas]

If you havent passsed -66 CAD you shouldnt have any combustion yet.

do you have any fuel?

[stefanke]

with the wedge geometry I run my simulation from -180 to 180 CA. Fuel is also injected and the temperatures are high enough so combustion process should take place!?!

[niklas]

did you set chemistry on in chemistryProperties?

If it doesnt burn you reactions are too slow.
That means that its either turned off or
that the reaction rate constant in chem.inp is too low.

[stefanke]

Niklas,

yes chemistry is on!

combustionProperties:
---------------------
chemistry on;

chemistrySolver ODE;
//chemistrySolver EulerImplicit;
//chemistrySolver sequential;

initialChemicalTimeStep 1.0e-7;

sequentialCoeffs
{
cTauChem 1.0e-3;
}

EulerImplicitCoeffs
{
cTauChem 5.0e-2;
equilibriumRateLimiter off;
}

ODECoeffs
{
ODESolver SIBS;
eps 5.0e-2;
scale 1.0;
}


I tried the the single step mechanism (chem.inp1) and chem.inp_15 delivered from the dieselFoam tutorial. I think the reation rates of this schemes should be ok or not?

Hi,everyone

Now I try to setup dieselEngineFoam.
It seems that there is no definition about injection timing in dieselFoam.
Where and How should I define it?

Hi,everyone

Now I try to setup dieselEngineFoam.
It seems that there is no definition about injection timing in dieselFoam.
Where and How should I define it?

Is there anybody who can help me ??

Atsushi

I run dieselEngineFoam of OF 1.3.

I got this error message.
--> FOAM FATAL IO ERROR : keyword cyclics is undefined in dictionary "/home/nishio/OpenFOAM/nishio-1.3/run/tutorials/dieselEngineFoam14/cyclic_test/- 180/p::boundaryField"

file: /home/nishio/OpenFOAM/nishio-1.3/run/tutorials/dieselEngineFoam14/cyclic_test/-1 80/p::boundaryField from line 31 to line 45.

From function dictionary::lookupEntry(const word& keyword) const
in file db/dictionary/dictionary.C at line 152.

this is dieselEngineFoam/test/-180/p.
dimensions [ 1 -1 -2 0 0 0 0 ];

internalField uniform 100000;

boundaryField
{
piston
{
type zeroGradient;
}

liner
{
type zeroGradient;
}

cylinderHead
{
type zeroGradient;
}
cyclics...
{
type zeroGradient;
}
}

What is wrong?

Please tell me.
thanks.

[hjasak]

You have either messed up the brackets or have hidden Microsoft endline characters (Ctrl-M) in the bit which says

cylinderHead
{
type zeroGradient;

cyclics...
{
type zeroGradient;
}
}

By the way, what are those dots after "cyclics"?

As a consequence, the solver cannot find the bit that says "cyclics" to locate the subdictionary.

There may be other things wrong as well, e.g. the boundary condition type on the cyclic boundary should be "cyclic", but the code will tell you what it thinks.

Good luck,

Hrv

I run dieselEngineFoam of tutorials.

Below,I show log dieselEngineFoam.

No Iterations of rho is 0. what happen?

Why this result occured?

Please teach me.

thanks.


Number of parcels in system | 2441
Injected liquid mass....... | 0.585093 mg
Liquid Mass in system...... | 0.556518 mg
SMD, Dmax.................. | 8.04166 mu, 144.482 mu
Added gas mass = 0.0285751 mg
Evaporation Continuity Error| -1.50067e-09 mg
ExecutionTime = 1403.97 s ClockTime = 1405 s

Mean and max Courant Numbers = 6.06171e-05 0.0998279
deltaT = 4.11218e-08
Crank angle = -14.8499 CA-deg
deltaZ = 8.26244e-08
clearance: 0.00709141
Piston speed = 2.00926 m/s
Solving chemistry
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterati
ons 0
BICCG: Solving for Ux, Initial residual = 0.00112271, Final residual = 6.95297e
-08, No Iterations 1
BICCG: Solving for Uy, Initial residual = 0.00110164, Final residual = 8.77127e
-07, No Iterations 1
BICCG: Solving for Uz, Initial residual = 0.00131305, Final residual = 2.67449e
-07, No Iterations 1
BICCG: Solving for C7H16, Initial residual = 0.00252406, Final residual = 3.952
72e-07, No Iterations 1
BICCG: Solving for O2, Initial residual = 0.00218811, Final residual = 3.20441e
-07, No Iterations 1
BICCG: Solving for CO2, Initial residual = 0.00116516, Final residual = 1.68511
e-07, No Iterations 1
BICCG: Solving for H2O, Initial residual = 0.00116516, Final residual = 1.68511
e-07, No Iterations 1
BICCG: Solving for h, Initial residual = 0.000129235, Final residual = 2.90022e
-08, No Iterations 1
ICCG: Solving for p, Initial residual = 0.0204819, Final residual = 3.29525e-13
, No Iterations 2
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterati
ons 0
time step continuity errors : sum local = 3.65186e-16, global = 2.63727e-16, cum
ulative = 4.27066e-12
ICCG: Solving for p, Initial residual = 8.59685e-05, Final residual = 2.52916e-
10, No Iterations 1
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterati
ons 0
time step continuity errors : sum local = 2.56815e-13, global = 7.56819e-15, cum
ulative = 4.27823e-12
BICCG: Solving for epsilon, Initial residual = 0.000555864, Final residual = 6.
98831e-08, No Iterations 1
BICCG: Solving for k, Initial residual = 0.000689, Final residual = 1.17105e-07
, No Iterations 1
Mean pressure:3.45583e+06
Mean temperature:914.791
Mean u':2.51441

Hello,

I try to setup dieselEngineFoam.
Now I don't understand amethod to "merge" the two cases to get a setup for the dieselEngine solver.
I want you to teach it in detail.

Thanks if you can help.

tanaka

Hi Tanaka,

You should check old log
↓↓
In Preprocessing/FoamX/dieselEngineFoam

Good luck!

Atsushi

Atsushi,

Thanks a lot for your help.
It's now working!

Hi,

"0" folder in dieselFoam ,
I can see "N2:0.766, O2:0.233" composition.

What kind of fraction?
Volume fraction or mass fraction?

Thanks.

Atsushi

mass fraction.
the solvers dieselFoam use it in the equations:
in createFields.
Hfor(label i=0; i<Y.size(); i++)
{
fields.add(Y[i]);
}
in Yeqn
solve
(
fvm::ddt(rho, Yi)
+ mvConvection->fvmDiv(phi, Yi)
- fvm::laplacian(turbulence->muEff(), Yi)
== kappa*chemistry.RR(i),
mesh.solver("Yi")
);
which is the mass conservation equation for a specie i, implying mass fraction Yi

Bruno

Bruno,

Thanks for your quick answer!


Atsu

Hello,

I want to know Reynolds number "Re" and viscosity "&mu;" of some cells per CA.

I found "sampleDict" in stressedFoam/plateHole/system.
Can I check "Re" and "&mu;" in dieselEngineFoam using sampleDict?

Thanks.

Atsu

[badiger]

Hello Sir,
I am new OpenFOAM,

I am trying to implementing Eddy Dissipation Concept, Can any body tell whether it is already there in OpenFOAM-1.5 or still to be implemented,
And give me some guidelines to set up a basic combustion problem in OpenFOAM

[markusrehm]

Hello Badiger,

I implemented it and have done a few test calculations but still it is not in a condition to be published. I hope to do that in a few weeks.

I showed it at the Workshop in Milan this year. If you want to I can send you the slides.

Regards, Markus.

[badiger]

Thanks Markus,

Please send, I ll go through,
Can you guide me in implementing a combustion problm, a simple one, some start ups i have already started with it, but stucking in writing chem.inp file requiring values of Activation energy etc.. for different fuels

Plz do the needful