[ayhan515]

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.

 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

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

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

----------------------------------------------------------------------------

checkMesh

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

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  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

[kaveh19]

hi ayhan515,
I want to run a HCCI,my thesis topic, engine .I can't fix my favorite compression .In fact I don't know how specify Vmin(clearance volume) and Vmax. please help me out.

[kaveh19]

Hi ayhan515,
Changing your mesh size maybe can help you.