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Old   October 2, 2008, 06:44
Default Hello! I have a problem wit
  #101
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Johan Svensson
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Hello!

I have a problem with the engineFoam tutorial and hope that someone here is able to give me some advice.
My task is to simulate a multi-spark ignition in a SI engine. So I am using the engineFoam/kivaTest case. When I have three ignitions at -30, -20 and -10 deg before TDC it crashes at -7.5 deg before TDC (timestep= 0.01), but with one ignition at -10 before TDC the computation goes on till 40 deg after TDC as I have chosen in the controlDict file. Am I supposed to use the controlDict.1st and controlDict.2nd for this, or when to use them?

I don't understand what kind of geometry I am supposed to generate in the polyMesh directory (there is already a mesh of a cylinder when using paraFoam). Now I have generated a small refined cubic mesh because I am interested in the spark in such a volume directly below the spark plug, but I am not sure at all about what mesh to produce and in that case how to place it in the right position below the spark position, and then what boundary conditions to use.

Thanks in advance,

Johan
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Old   January 13, 2009, 03:46
Default Hi! Is there anyone who can
  #102
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Johan Svensson
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Hi!

Is there anyone who can give me some references to literature about the physical model that engineFoam is built on? In the beginning of this thread some links are mentioned but unfortunately they don't work. I am doing my master thesis and need to add some background theory about engineFoam to my report.

Kind regards,

Johan
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Old   March 11, 2009, 08:59
Default Hi. I'm trying to implement th
  #103
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John Paul Handrigan
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Hi. I'm trying to implement the Eddy Breakup Model in OpenFOAM. I'm just wondering if anyone has successfully done this before? Thanks.

JPH
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Old   March 23, 2009, 08:57
Default Simulation of 1/4 of a combustion chamber?
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Tomislav Sencic
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Hello,

I am using dieselFoam to simulate the injection and combustion of fuel in a constant volume chamber. When I try to simulate just a quarter of the chamber to save calculation time (wity sym boundaries and the injector in 0,0,0 position) I get a 4x greater pressure rise. If I would inject just 1/4 of the fuel mass, the spray properties, and evaporation rate would change, it would be a different condition!
How can I simulate just 1/4 of the injectin chamber?

Tomislav
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Old   March 23, 2009, 10:02
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  #105
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Quote:
Originally Posted by tsencic View Post
Hello,

I am using dieselFoam to simulate the injection and combustion of fuel in a constant volume chamber. When I try to simulate just a quarter of the chamber to save calculation time (wity sym boundaries and the injector in 0,0,0 position) I get a 4x greater pressure rise. If I would inject just 1/4 of the fuel mass, the spray properties, and evaporation rate would change, it would be a different condition!
How can I simulate just 1/4 of the injectin chamber?
The injection does not know about the boundary conditions. So if you have 1/4 of the volume, you have to inject 1/4 of the mass also.
Everything is the same except for the mass in injectionProperties.

And I think you should use cyclic bc's and not symmetric.
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Old   March 25, 2009, 13:44
Default Modelling Sandia's Flame D
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John Paul Handrigan
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Hi. I'm trying to model Sandia's Flame D in openFoam. However, the flame seems to blow off with the current model. I'm using reactingFoam as the solver. Has anyone had a similar experience to this?

Here's a site with more information about Flame D.

http://www.ca.sandia.gov/TNF/DataArch/FlameD.html

Thanks in advance for any advice you may have!

John Paul Handrigan
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Old   March 25, 2009, 14:30
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M. Mahdi Salehi
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Hi John,
I had the experience of simulating a Pilot flame like Sandia D, but it was premixed, I used reactingFoam. I had the same problem by using simple one-step chemistry. I used a 5-step chemistry and then I could get a converged solution. However, the solution was not satisfactory. Such flames are highly stained; thus, require good closure for turbulence chemistry interactions. I can give you the 5-tep chemisty that I used if you want.
cheers,
Mahdi
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Old   March 25, 2009, 15:15
Default Sandia
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John Paul Handrigan
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Quote:
Originally Posted by smehdi609 View Post
Hi John,
I had the experience of simulating a Pilot flame like Sandia D, but it was premixed, I used reactingFoam. I had the same problem by using simple one-step chemistry. I used a 5-step chemistry and then I could get a converged solution. However, the solution was not satisfactory. Such flames are highly stained; thus, require good closure for turbulence chemistry interactions. I can give you the 5-tep chemisty that I used if you want.
cheers,
Mahdi
Mahdi,
I'd really appreciate the 5-step chemistry that you used. How can I get this information from you? e-mail? My e-mail address is jhand085@uottawa.ca . Thanks for the quick reply!

John Paul
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Old   April 24, 2010, 14:05
Default Those links are not working
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Ramesh
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Hello Henry,

Links given by you are not working, kindly help me I want the report on which XiFoam is based. I am working on turbulent premixed flames.I also want to know about these reactants,products & burnt products in thermophysicalProperties file of moriyoHomogeneous case. kindly help me. If I want any other hydrocarbon instaed of propane, what values I shall change here in thermophysicalProperties file,.


Thanks in Advance
Ramesh
Kingston University
London

Quote:
Originally Posted by Henry Weller (Henry) View Post
Currently the FOAM premixed/partially-premixed combustion codes are supplied with the Weller flamelet combustion model. This was originally developed by me while I was at Imperial College and the first report I wrote on it is available from
ftp://monet.me.ic.ac.uk/pub/papers/TF9307.ps.gz However I have developed and expended the model significantly since then and the latest implementation in FOAM is a a form I originally developed for LES http://monet.me.ic.ac.uk/publications/abstracts.html#Welleretal:1998
from which I redeveloped a RANS version. There is also a second publication on the final model in the proceedings of the 28th Combustion Symposium.

If you have trouble finding either of these papers let me know and I will dig them out for you.
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Old   June 25, 2011, 12:03
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  #110
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Francesca
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Hello Henry,
just like Ramesh I would like to know something about the b-Xi model but the links you gave a bit time ago do not work. Could you send me some informations or docs about it?
My e-mail adress is:
francesca.scaramuzzino86@gmail.com

Thanks a lot
Francesca
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Old   October 24, 2011, 06:17
Default
  #111
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Quote:
Originally Posted by niklas View Post
the dieselSpray class has a liquid length penetration function that you can use.

dieselSpray.liquidPenetration(prc)

where prc is the percentage of how much of the liquid you want to use for defining the liquid penetration.

so if you use

dieselSpray.liquidPenetration(1.0)

it will use all of the liquid to calculate the penetration, but if you use

dieselSpray.liquidPenetration(0.98)

it will not use the 2% most far away from the injector.

the other parameters, you have to calculate/define yuorself.

N
Hello Niklas, I m new to foam, please can u elaborate a little that how can we use this function to use liquid penetration. Thanks a lot.
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Old   November 24, 2011, 11:31
Unhappy premixed heptane-air combustion in a diesel engine (HCCI)
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Ayhan Eses
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Dear Foamers/masters,


I would like to model premixed heptane-air combustion in a diesel engine (HCCI).

  • So I modified dieselEngineFoam source codes and I disabled lines about spray.
  • I added a C7H16 file similar to N2 and O2 for its Y fraction in -180 folder.
  • I use a global reaction mechanism for heptane combustion.
Code:
 C7H16 + 11O2            => 7CO2 + 8H2O        5.00E+8  0.0   15780.0! 1
  • I modified engineFoam-kivaTest mesh and increase its compression ratio.








I used decomposePar
Code:
numberOfSubdomains 8;

method          simple;

simpleCoeffs
{
    n               (4 2 1);
    delta           0.001;
}
The case started(-180) on 22.Nov.2011-16.51
The time period between (-180) and (-35) seems reasonable. It's ok.

When it came to (-35) on 22.Nov.2011-18.41 I changed controlDict files to reduce Co number.

//for (-180,-35) deltaT 0.05;
//for (-35, 30)
deltaT 2.5e-06;

//for (-180,-35) writeInterval 5.0;
//for (-35, 30)
writeInterval 1.0;

//for (-180,-35) adjustTimeStep no;
//for (-35, 30)
adjustTimeStep yes;

It was started(from -35) again 22.Nov.2011-19.12
It came to -19.999787 22.Nov.2011-21.40
The time period between (-35) (19.999787) seems reasonable. It's ok.

Pressure and temperature values seem normal.

But now on 24.Nov.2011-16.26 it is at -19.7257779 and still running.


Just 0,2740091 degree difference took 1 day 18 hour 46 min. time period.

Is that last situation normal? What should I do to fix this?



I tried to describe my problem more clearly. I hope you understand what I mean.
If you give any suggestion/solution, I would be very pleased.

I am looking forward to hearing from you soon. Thanks in advance.

Best regards.

Ayhan

----------------------------------------------------------------------------
engineCompRatio
Code:
ayhan@ayhan:~/Masaüstü/tutorials öğesine bağlantı/dizelim2015-12N-8-islemci-22112011$ engineCompRatio 
/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.0.1                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : 2.0.1-51f1de99a4bc
Exec   : engineCompRatio
Date   : Nov 24 2011
Time   : 14:52:32
Host   : ayhan
PID    : 1614
Case   : /home/ayhan/OpenFOAM/ayhan-2.0.1/run/tutorials/dizelim2015-12N-8-islemci-22112011
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Disallowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create engine time

Create mesh for time = -180

Selecting engineMesh layered
deckHeight: 0.0617697
piston position: -0.00374205
CA = 180
deltaZ = 0
clearance: 0.0655117
Piston speed = 0 m/s
CA = 360
deltaZ = 0.068
clearance: -0.00248827
Piston speed = 4.98667 m/s

Vmax = 0.000408381, Vmin = 2.66865e-05
Vmax/Vmin = 15.3029

End
----------------------------------------------------------------------------
Code:
checkMesh
Code:
ayhan@ayhan:~/Masaüstü/tutorials öğesine bağlantı/dizelim2015-12N-8-islemci-22112011$ checkMesh 
/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.0.1                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : 2.0.1-51f1de99a4bc
Exec   : checkMesh
Date   : Nov 24 2011
Time   : 14:53:11
Host   : ayhan
PID    : 1625
Case   : /home/ayhan/OpenFOAM/ayhan-2.0.1/run/tutorials/dizelim2015-12N-8-islemci-22112011
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Disallowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create polyMesh for time = -180

Time = -180

Mesh stats
    points:           32397
    faces:            87320
    internal faces:   77944
    cells:            27544
    boundary patches: 4
    point zones:      0
    face zones:       1
    cell zones:       1

Overall number of cells of each type:
    hexahedra:     27544
    prisms:        0
    wedges:        0
    pyramids:      0
    tet wedges:    0
    tetrahedra:    0
    polyhedra:     0

Checking topology...
    Boundary definition OK.
    Cell to face addressing OK.
    Point usage OK.
    Upper triangular ordering OK.
    Face vertices OK.
   *Number of regions: 2
    The mesh has multiple regions which are not connected by any face.
  <<Writing region information to "-180/cellToRegion"

Checking patch topology for multiply connected surfaces ...
    Patch               Faces    Points   Surface topology                  
    liner               2596     2866     ok (non-closed singly connected)  
    piston              1326     1400     ok (non-closed singly connected)  
    cylinderHead        2184     2260     ok (non-closed singly connected)  
    default-exterior    3270     3421     ok (non-closed singly connected)  

Checking geometry...
    Overall domain bounding box (-0.04301 -0.0429955 -0.00721194) (0.04301 0.0429955 0.0679594)
    Mesh (non-empty, non-wedge) directions (1 1 1)
    Mesh (non-empty) directions (1 1 1)
    Boundary openness (1.58789e-19 2.28627e-19 1.8564e-19) OK.
    Max cell openness = 2.43625e-16 OK.
    Max aspect ratio = 28.098 OK.
    Minumum face area = 1.24075e-07. Maximum face area = 2.97139e-05.  Face area magnitudes OK.
    Min volume = 1.03618e-10. Max volume = 9.1877e-08.  Total volume = 0.000408381.  Cell volumes OK.
    Mesh non-orthogonality Max: 83.9266 average: 30.6664
   *Number of severely non-orthogonal faces: 1724.
    Non-orthogonality check OK.
  <<Writing 1724 non-orthogonal faces to set nonOrthoFaces
    Face pyramids OK.
    Max skewness = 3.36545 OK.

Mesh OK.

End



log
Code:
/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.0.x                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : 2.0.x-29c61267b203
Exec   : dizelim2015 -parallel
Date   : Nov 22 2011
Time   : 16:52:32
Host   : d135.uybhmitu.edu
PID    : 3461
Case   : dizelim2015-12N-8-islemci-22112011
nProcs : 8
Slaves : 
7
(
:
:
:
:
:
)

Pstream initialized with:
    floatTransfer     : 0
    nProcsSimpleSum   : 0
    commsType         : nonBlocking
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Disallowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create engine time

Create mesh for time = -180


Selecting engineMesh layered
deckHeight: 0.0617697
piston position: -0.00374205

Reading thermophysicalProperties


Selecting psiChemistryModel ODEChemistryModel<gasThermoPhysics>
Selecting thermodynamics package hsPsiMixtureThermo<reactingMixture<gasThermoPhysics>>
Selecting chemistryReader chemkinReader
ODEChemistryModel: Number of species = 5 and reactions = 1
Selecting ODE solver SIBS
Reading field U


Reading/calculating face flux field phi

Creating turbulence model.

Selecting turbulence model type RASModel
Selecting RAS turbulence model kEpsilon
kEpsilonCoeffs
{
    Cmu             0.09;
    C1              1.44;
    C2              1.92;
    C3              -0.33;
    sigmak          1;
    sigmaEps        1.3;
    Prt             1;
}

Creating field DpDt


Reading g
Reading combustion properties

Courant Number mean: 0 max: 0
Total cylinder mass: 0.0003676

PIMPLE: no residual control data found. 
Calculations will employ 3 corrector loops


Starting time loop

Courant Number mean: 0 max: 0
Krank acisi = -179.95 KA-derece
deltaZ = 9.21597e-09
clearance: 0.0655117
Piston speed = 0.00243302 m/s
Solving chemistry
, T = 373, p = 95600, C7H16 = 0.0169514
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
PIMPLE: iteration 1
DILUPBiCG:  Solving for C7H16, Initial residual = 0.999971, Final residual = 6.261e-14, No Iterations 9
DILUPBiCG:  Solving for O2, Initial residual = 1, Final residual = 6.26118e-14, No Iterations 9
DILUPBiCG:  Solving for CO2, Initial residual = 1, Final residual = 6.26118e-14, No Iterations 9
DILUPBiCG:  Solving for H2O, Initial residual = 1, Final residual = 6.26118e-14, No Iterations 9
DILUPBiCG:  Solving for hs, Initial residual = 1, Final residual = 0.00217333, No Iterations 1
DICPCG:  Solving for p, Initial residual = 1, Final residual = 0.0580049, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.0412122, Final residual = 0.00206164, No Iterations 2
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 1.57257e-08, global = 5.55614e-09, cumulative = 5.55614e-09
PIMPLE: iteration 2
DILUPBiCG:  Solving for C7H16, Initial residual = 0.0028216, Final residual = 5.7904e-13, No Iterations 8
DILUPBiCG:  Solving for O2, Initial residual = 0.0014441, Final residual = 1.22784e-13, No Iterations 8
DILUPBiCG:  Solving for CO2, Initial residual = 3.55091e-05, Final residual = 7.97566e-13, No Iterations 6
DILUPBiCG:  Solving for H2O, Initial residual = 3.55084e-05, Final residual = 7.97231e-13, No Iterations 6
DILUPBiCG:  Solving for hs, Initial residual = 0.0336152, Final residual = 7.63924e-05, No Iterations 1
DICPCG:  Solving for p, Initial residual = 0.0497545, Final residual = 0.00252405, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00501676, Final residual = 0.000458723, No Iterations 2
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 4.25382e-09, global = 1.59641e-09, cumulative = 7.15255e-09
PIMPLE: iteration 3
DILUPBiCG:  Solving for C7H16, Initial residual = 0.00257326, Final residual = 2.46875e-13, No Iterations 8
DILUPBiCG:  Solving for O2, Initial residual = 0.00139858, Final residual = 4.01771e-13, No Iterations 8
DILUPBiCG:  Solving for CO2, Initial residual = 4.88702e-07, Final residual = 2.08857e-15, No Iterations 6
DILUPBiCG:  Solving for H2O, Initial residual = 4.8861e-07, Final residual = 2.10063e-15, No Iterations 6
DILUPBiCG:  Solving for hs, Initial residual = 0.00744226, Final residual = 2.14878e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.011001, Final residual = 0.000754799, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00141697, Final residual = 6.05589e-05, No Iterations 3
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 5.87022e-10, global = 3.09467e-10, cumulative = 7.46201e-09
DILUPBiCG:  Solving for epsilon, Initial residual = 0.00173338, Final residual = 2.16273e-06, No Iterations 1
DILUPBiCG:  Solving for k, Initial residual = 1, Final residual = 6.99123e-07, No Iterations 4
Mean pressure:95600.1
Mean temperature:373
Mean u':1.63224
ExecutionTime = 1.63 s  ClockTime = 5 s


:
:
:
:
:

Courant Number mean: 0.00451027 max: 0.0533268
Krank acisi = -35 KA-derece
deltaZ = 2.11031e-05
clearance: 0.00528321
Piston speed = 5.57122 m/s
Solving chemistry
, T = 382.207, p = 96283.4, C7H16 = 0.0169512
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
PIMPLE: iteration 1
DILUPBiCG:  Solving for C7H16, Initial residual = 0.0645808, Final residual = 1.43178e-13, No Iterations 8
DILUPBiCG:  Solving for O2, Initial residual = 0.0645809, Final residual = 1.46181e-13, No Iterations 8
DILUPBiCG:  Solving for CO2, Initial residual = 0.0645809, Final residual = 2.20095e-13, No Iterations 8
DILUPBiCG:  Solving for H2O, Initial residual = 0.0645809, Final residual = 2.20095e-13, No Iterations 8
DILUPBiCG:  Solving for hs, Initial residual = 0.0426634, Final residual = 8.38464e-05, No Iterations 1
DICPCG:  Solving for p, Initial residual = 0.005583, Final residual = 0.000483398, No Iterations 4
DICPCG:  Solving for p, Initial residual = 0.000500225, Final residual = 4.84631e-05, No Iterations 6
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 0.000117224, global = 4.3641e-05, cumulative = 0.0103119
PIMPLE: iteration 2
DILUPBiCG:  Solving for C7H16, Initial residual = 3.78284e-05, Final residual = 6.74487e-14, No Iterations 6
DILUPBiCG:  Solving for O2, Initial residual = 3.78292e-05, Final residual = 9.34363e-14, No Iterations 6
DILUPBiCG:  Solving for CO2, Initial residual = 3.78292e-05, Final residual = 7.20297e-14, No Iterations 7
DILUPBiCG:  Solving for H2O, Initial residual = 3.78292e-05, Final residual = 7.20297e-14, No Iterations 7
DILUPBiCG:  Solving for hs, Initial residual = 0.000366113, Final residual = 9.65849e-06, No Iterations 1
DICPCG:  Solving for p, Initial residual = 0.000138196, Final residual = 1.03483e-05, No Iterations 5
DICPCG:  Solving for p, Initial residual = 2.80019e-05, Final residual = 2.65778e-06, No Iterations 5
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 6.43053e-06, global = 2.95708e-06, cumulative = 0.0103149
PIMPLE: iteration 3
DILUPBiCG:  Solving for C7H16, Initial residual = 3.31784e-05, Final residual = 1.54592e-13, No Iterations 6
DILUPBiCG:  Solving for O2, Initial residual = 3.31791e-05, Final residual = 8.57671e-14, No Iterations 6
DILUPBiCG:  Solving for CO2, Initial residual = 3.31791e-05, Final residual = 5.75564e-13, No Iterations 6
DILUPBiCG:  Solving for H2O, Initial residual = 3.31791e-05, Final residual = 5.75564e-13, No Iterations 6
DILUPBiCG:  Solving for hs, Initial residual = 0.000153014, Final residual = 3.74179e-07, No Iterations 1
DICPCG:  Solving for p, Initial residual = 2.08601e-05, Final residual = 1.8431e-06, No Iterations 5
DICPCG:  Solving for p, Initial residual = 5.37536e-06, Final residual = 6.35646e-07, No Iterations 4
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 1.53798e-06, global = 2.68049e-07, cumulative = 0.0103151
DILUPBiCG:  Solving for epsilon, Initial residual = 0.00263629, Final residual = 4.19019e-06, No Iterations 1
DILUPBiCG:  Solving for k, Initial residual = 0.00292238, Final residual = 8.76681e-06, No Iterations 1
Mean pressure:2.14728e+06
Mean temperature:974.471
Mean u':1.69924
ExecutionTime = 3810.6 s  ClockTime = 6535 s
Attached Images
File Type: jpg pressure.jpg (71.5 KB, 31 views)
File Type: jpg temperature.jpg (72.1 KB, 27 views)

Last edited by ayhan515; November 24, 2011 at 15:34.
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Old   December 18, 2011, 02:08
Default Running a non-combustion case with dieselEngineFoam
  #113
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Carl
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Dear Foamers,

I am currently running a motored case simulation with dieselEngineFoam. I delayed the SOI to very late so that no fuel is delivered with the 1st cycle (-180 to 180). However, the simulation seemed to stop at Top Dead Centre because the timestep did not progress anymore after I waited for quite some time. No error message appeared in the log file and hence I couldn’t really sort of the reason. I anyhow observed that the piston speed and deltaZ turned into negative numbers when the piston reaches TDC.

Courant Number mean: 0.00302152 max: 0.247541
deltaT = 5.14141e-07
Crank angle = 0.0238475 CA-deg
deltaZ = -2.36259e-09
clearance: 0.00210001
Piston speed = -0.00459523 m/s

Can anyone give me a little advice why did the simulation just ‘stop’ at TDC?

The following are my input for blockMeshDict, boundary.org, engineGeometry, pressure boundary condition as well as the controlDict file.

For all the boundary conditions, I basically added ‘cyclic’ for ‘cyclic patch’ and ‘empty’ for ‘empty patch’. Am I correct to set so?

Many thanks in advance. It would be a great help if anyone of you could point out my mistakes in the input.

Thanks again.

Best regards,
Carl.

blockMeshDict
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

convertToMeters 0.01;

vertices

(
(0 0 0) //Vertex 0
(-0.187132 0.451777 0) //Vertex 1
(-1.871321 4.517771 0) //Vertex 2
(0 0 1.55) //Vertex 3
(-0.187132 0.451777 1.55) //Vertex 4
(-1.871321 4.517771 1.55) //Vertex 5
(0.187132 0.451777 0) //Vertex 6
(1.871321 4.517771 0) //Vertex 7
(0.187132 0.451777 1.55) //Vertex 8
(1.871321 4.517771 1.55) //Vertex 9
(0 0 17) //Vertex 10
(-0.187132 0.451777 17) //Vertex 11
(-1.871321 4.517771 17) //Vertex 12
(-2.673044 6.453299 17) //Vertex 13
(0.187132 0.451777 17) //Vertex 14
(1.871321 4.517771 17) //Vertex 15
(2.673044 6.453299 17) //Vertex 16
(-2.673044 6.453299 1.55) //Vertex 17
(2.673044 6.453299 1.55) //Vertex 18
);

blocks

(
hex (1 0 0 6 4 3 3 8) (3 19 5) simpleGrading (1 1 1) //prism for bowl
hex (2 1 6 7 5 4 8 9) (15 19 5) simpleGrading (1 1 1) //hex for bowl
hex (4 3 3 8 11 10 10 14) (3 19 52) simpleGrading (1 1 1) //prism for main stroke
hex (5 4 8 9 12 11 14 15) (15 19 52) simpleGrading (1 1 1) //hex for main stroke inner
hex (17 5 9 18 13 12 15 16) (7 19 52) simpleGrading (1 1 1) //hex for main stroke outer
);
//hex (1 0 0 6 4 3 3 8) (10 19 11) simpleGrading (1 1 1) Martini
//hex (2 1 6 7 5 4 8 9) (20 19 11) simpleGrading (1 1 1) Martini

edges
(
arc 1 6 (0 0.489 0)
arc 2 7 (0 4.89 0)
arc 4 8 (0 0.489 1.55)
arc 5 9 (0 4.89 1.55)
arc 11 14 (0 0.489 17)
arc 12 15 (0 4.89 17)
arc 13 16 (0 6.985 17)
arc 17 18 (0 6.985 1.55)
);

patches
(
wall liner
(
(17 18 16 13)
)
wall piston
(
(0 1 6 0)
(6 7 2 1)
(2 7 9 5)
(9 18 17 5)
)
wall cylinderHead
(
(10 14 11 10)
(14 15 12 11)
(15 16 13 12)
)
cyclic cyclic
(
(0 6 8 3) //positive, prism, bowl
(6 7 9 8) //positive, hex, bowl
(3 8 14 10) //positive, prism, main stroke
(8 9 15 14) //positive, hex, main stroke inner
(9 18 16 15) //positive, hex, main stroke outer
(0 1 4 3) //negative, prism, bowl
(1 2 5 4) //negative, hex, bowl
(3 4 11 10) //negative, prism, main stroke
(4 5 12 11) //negative, hex, main stroke inner
(5 17 13 12) //negative, hex, main stroke outer
)
empty center
(
(0 3 3 0)
(3 10 10 3)
)
);

mergePatchPairs
(
);

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

boundary.org
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

5
(
piston
{
type wall;
physicalType fixedTemperatureMovingWallFunctions;
nFaces 1083;
startFace 288493;
}

liner
{
type wall;
physicalType fixedTemperatureWallFunctions;
nFaces 1957;
startFace 286536;
}

cylinderHead
{
type wall;
physicalType fixedTemperatureWallFunctions;
nFaces 893;
startFace 289576;
}

cyclic
{
type cyclic;
physicalType cyclic;
nFaces 10342;
startFace 290469;
featureCos 0.9;
}

center
{
type empty;
physicalType empty;
nFaces 0;
startFace 300811;
}
)

engineGeometry
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

engineMesh layered;

conRodLength conRodLength [ 0 1 0 0 0 0 0 ] 0.3048;

bore bore [ 0 1 0 0 0 0 0 ] 0.1397;

stroke stroke [ 0 1 0 0 0 0 0 ] 0.1524;

clearance clearance [ 0 1 0 0 0 0 0 ] 0.002;

rpm rpm [ 0 0 -1 0 0 0 0 ] 1200;


// ************************************************** *********** //


-180/p
// ************************************************** *********** //
dimensions [1 -1 -2 0 0 0 0];

internalField uniform 233000;

boundaryField
{
piston
{
type zeroGradient;
}

liner
{
type zeroGradient;
}

cylinderHead
{
type zeroGradient;
}

cyclic
{
type cyclic;
}

center
{
type empty;
}
}


// ************************************************** *********** //


controlDict:

application dieselEngineFoam;

startFrom startTime;

startTime -180;

stopAt endTime;

endTime 180;

deltaT 0.025;

writeControl runTime;

writeInterval 5;

purgeWrite 0;

writeFormat ascii;

writePrecision 6;

writeCompression uncompressed;

timeFormat general;

timePrecision 6;

runTimeModifiable yes;

adjustTimeStep yes;

maxCo 0.2;

maxDeltaT 1;
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Old   December 18, 2011, 10:19
Default
  #114
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Carl
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Any clue?

Last edited by carl_xw4; December 18, 2011 at 10:41. Reason: I made a mistake!
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Old   December 19, 2011, 07:16
Arrow
  #115
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Ayhan Eses
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Quote:
Originally Posted by carl_xw4 View Post
Dear Foamers,

I am currently running a motored case simulation with dieselEngineFoam. I delayed the SOI to very late so that no fuel is delivered with the 1st cycle (-180 to 180). However, the simulation seemed to stop at Top Dead Centre because the timestep did not progress anymore after I waited for quite some time. No error message appeared in the log file and hence I couldn’t really sort of the reason. I anyhow observed that the piston speed and deltaZ turned into negative numbers when the piston reaches TDC.

Courant Number mean: 0.00302152 max: 0.247541
deltaT = 5.14141e-07
Crank angle = 0.0238475 CA-deg
deltaZ = -2.36259e-09
clearance: 0.00210001
Piston speed = -0.00459523 m/s

Can anyone give me a little advice why did the simulation just ‘stop’ at TDC?

The following are my input for blockMeshDict, boundary.org, engineGeometry, pressure boundary condition as well as the controlDict file.

For all the boundary conditions, I basically added ‘cyclic’ for ‘cyclic patch’ and ‘empty’ for ‘empty patch’. Am I correct to set so?

Many thanks in advance. It would be a great help if anyone of you could point out my mistakes in the input.

Thanks again.

Best regards,
Carl.
Hi Carl,
I am not a specialist but i tried to find out your problem.

i use
Code:
engineCompRatio
to check your compression ratio.




Code:
ayhan@ayhan:~/paylasilan/uybh/carl$ engineCompRatio 
/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.0.1                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : 2.0.1-51f1de99a4bc
Exec   : engineCompRatio
Date   : Dec 19 2011
Time   : 13:01:08
Host   : ayhan
PID    : 2108
Case   : /home/ayhan/paylasilan/uybh/carl
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Disallowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create engine time

Create mesh for time = -180

Selecting engineMesh layered
deckHeight: 17
piston position: 1.55
CA = 0
deltaZ = 0.1524
clearance: 15.2976
Piston speed = 6.096 m/s

Vmax = 310.486, Vmin = 307.567
Vmax/Vmin = 1.00949

End
As it seen on above your compression ratio is about 1.

And another problem units.
Your max. volume is Vmax = 310.486 m3,

it should be Vmax = 0.000310486 m3

clearance: 15.2976 meter

I think your geometry, shape, is ok.

Maybe i am wrong.
I think problem about blockMesh units. How could you build blockMesh? I really wonder which tool was used for blockmesh. I use Fluent mesh for engine geometry. I think you need a conversation factor or change the units of your software or re-scale it. (meter>>milimeter).

And for a motored case -180/p 233000 pa 2,33 bar, i think you should change this value with atmosferic pressure.

Sorry my English is not well
Best regards.

Last edited by ayhan515; December 20, 2011 at 04:50.
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Old   December 21, 2011, 10:47
Default
  #116
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Carl
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Hi

Thanks for your reply.

I have actually converted the unit to meters. This is what I have generated with engineCompRatio:

Create engine time

Create mesh for time = -180

Selecting engineMesh layered
deckHeight: 0.17
piston position: 0.0155
CA = 0
deltaZ = 0.1524
clearance: 0.0021
Piston speed = 6.096 m/s

Vmax = 0.000310486, Vmin = 1.85732e-05
Vmax/Vmin = 16.7169

I apologise if I didn't write my problem clearly.

By the way, I managed to solve the problem. I actually stupidly included a not sensible mass flow rate in the fuel injection properties file. That causes the simulation to stop. Sorry!

Best regards,
Carl.
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Old   January 30, 2012, 05:24
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  #117
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Hello Henry,
like Ramesh and Francesca I research documents to understand the b-Xi model but the links you gave a long time ago do not work. I also want to know about the reactants,products & burnt products in thermophysicalProperties file and how to determine these parameters for new fuel and oxydant. Could you send me some informations or documents about it?
My e-mail adress is:
baptiste.lebrun@yahoo.fr

Thanks a lot
Baptiste


Quote:
Originally Posted by rameshbvb View Post
Hello Henry,

Links given by you are not working, kindly help me I want the report on which XiFoam is based. I am working on turbulent premixed flames.I also want to know about these reactants,products & burnt products in thermophysicalProperties file of moriyoHomogeneous case. kindly help me. If I want any other hydrocarbon instaed of propane, what values I shall change here in thermophysicalProperties file,.


Thanks in Advance
Ramesh
Kingston University
London
Quote:
Originally Posted by Francesca Scaramuzzino View Post
Hello Henry,
just like Ramesh I would like to know something about the b-Xi model but the links you gave a bit time ago do not work. Could you send me some informations or docs about it?
My e-mail adress is:
francesca.scaramuzzino86@gmail.com

Thanks a lot
Francesca
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Old   September 30, 2014, 09:42
Default
  #118
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Wen Xu
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Quote:
Originally Posted by Henry Weller (Henry) View Post
Currently the FOAM premixed/partially-premixed combustion codes are supplied with the Weller flamelet combustion model. This was originally developed by me while I was at Imperial College and the first report I wrote on it is available from
ftp://monet.me.ic.ac.uk/pub/papers/TF9307.ps.gz However I have developed and expended the model significantly since then and the latest implementation in FOAM is a a form I originally developed for LES http://monet.me.ic.ac.uk/publications/abstracts.html#Welleretal:1998
from which I redeveloped a RANS version. There is also a second publication on the final model in the proceedings of the 28th Combustion Symposium.

If you have trouble finding either of these papers let me know and I will dig them out for you.
hi,henry. I cannt find the ftp://monet.me.ic.ac.uk/pub/papers/TF9307.ps.gz and http://monet.me.ic.ac.uk/publications/abstracts.html, can you send them to me. 981588592@qq.com. Thank you very much!
wen
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Old   October 4, 2014, 10:42
Default
  #119
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Bruno Santos
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wyldckat is just really nicewyldckat is just really nicewyldckat is just really nicewyldckat is just really nice
Quick answer: snapshots of the old abstract page can still be found at the Wayback Machine website: http://web.archive.org/web/200405120...abstracts.html

Then it's just a matter of looking for the paper by its title...
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