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skherad July 6, 2006 04:45

Dear all I have a problem in
 
Dear all
I have a problem in dieselFoam(aachenBomb case). I could not predict the right place of autoignition(I think it should be in shear layer but in the simulations it is in front of spray tip). the setup is as follow:
openFoan: 1.1
geometry and mesh: 2d(30mm*100mm) , 80*120

chemistrySolver EulerImplicit(it is faster than ODE)
cTauChem 5.0e-2;
equilibriumRateLimiter off

combustionProperties
cmix 1.0



injectorType unitInjector;
unitInjectorProps
{
position (0.0001 0 0);
direction (1 0 0);
diameter 0.0002;
Cd 0.9;
mass 6e-06;
temperature 350;
nParcels 5000;

X
(
1.0
);

massFlowRateProfile
(
(0 5.4)
(0.00005 6.7)
(0.0001 6.55)
(0.00015 6.4)
(0.0002 5.8)
(0.00025 5.5)
(0.0003 5.75)
(0.00035 6.05)
(0.0004 6.1)
(0.00045 6.15)
(0.0005 5.75)
(0.00055 5.2)
(0.0006 5.1)
(0.00065 5)
(0.0007 4.8)
(0.00075 4.8)
(0.0008 4.5)
(0.00085 3.2)
(0.0009 3.2)
(0.00095 3.1)
(0.0010 3)
(0.00105 3.1)
(0.0011 3.2)
(0.00115 3.15)
(0.0012 2.2)
(0.00125 1.8)
);
}


sprayProperties
interpolationSchemes
{
U cellPointFace;
rho cell;
p cell;
T cell;
}

subCycles 2;

atomizationModel off;
includeOscillation yes;
breakupModel ReitzKHRT;
injectorModel hollowConeInjector;
collisionModel off;
evaporationModel standardEvaporationModel;
heatTransferModel RanzMarshall;
dispersionModel off;
dragModel standardDragModel;
wallModel reflect;
specConstAtomizationCoeffs
{
dropletNozzleDiameterRatio
(
0.4
);
sprayAngle
(
15
);
}

ReitzKHRTCoeffs
{
B0 0.61;
B1 40;
Ctau 1;
CRT 0.1;
msLimit 0.2;
WeberLimit 6;
}

trajectoryCoeffs
{
cSpace 1;
cTime 0.3;
}

standardDragModelCoeffs
{
preReFactor 0.166667;
ReExponent 0.666667;
ReLimiter 1000;
CdLimiter 0.44;
Cdistort 2.632;
}


RanzMarshallCoeffs
{
preRePrFactor 0.6;
ReExponent 0.5;
PrExponent 0.333333;
}

hollowConeInjectorCoeffs
{
dropletPDF
{
pdfType RosinRammler;

RosinRammlerPDF
{
minValue 1.00e-6;
maxValue 1.50e-4;

d
(
1.5e-4
);

n
(
3
);
}
exponentialPDF
{
minValue 1.0e-4;
maxValue 1.0e-3;

lambda
(
1.0e+4
);
}
}

innerConeAngle
(
0.0
);

outerConeAngle
(
15.0
);
}

reflectCoeffs
{
elasticity 0.9;
}


thermodynamicProperties;
thermoType hMixtureThermo<reactingmixture>;
CHEMKINFile "$FOAM_ROOT/$FOAM_CASE/chemkin/chem.inp";
CHEMKINThermoFile "$FOAM_ROOT/$FOAM_CASE/chemkin/therm.dat";

inertSpecie N2;
stoichiometricAirFuelMassRatio1 stoichiometricAirFuelMassRatio [0 0 0 0 0 0 0] 14.9207;
burntProducts1 burntProducts 1 28.5809
200 6000 1000
3.12297 0.00178679 -5.94666e-07 9.09361e-11 -5.12055e-15 -11005.6 5.04351
3.47795 0.000748332 -3.54025e-07 1.3343e-09 -8.05648e-13 -11072.3 3.29518
-10002.9
1.67212e-6 170.672;

liquidFuelComponents
(
C7H16
);

C7H16 C7H16 defaultCoeffs;


turbulenceModel kEpsilon;
turbulence on;
kEpsilonCoeffs
{
Cmu Cmu [0 0 0 0 0 0 0] 0.09;
C1 C1 [0 0 0 0 0 0 0] 1.44;
C2 C2 [0 0 0 0 0 0 0] 1.92;
C3 C3 [0 0 0 0 0 0 0] -0.33;
alphah alphah [0 0 0 0 0 0 0] 1;
alphak alphak [0 0 0 0 0 0 0] 1;
alphaEps alphaEps [0 0 0 0 0 0 0] 0.76923;
muLimiter on;
Lsgs Lsgs [0 1 0 0 0 0 0] 0.0002;

}

chem.inp:
I have tested all files in the code(OpenFOAM-1.1/applications/test/readCHEMKINIII/CHEMKINdata)
and some other files(in Dr Nordin Website and Dr Feng Tao papers).


questions
1-Is the Cmix=1.0 correct? (Dr Nordin recommanded other values in his thesis)
2-are the arrhenius rate coeficients correct in the chem.inp files in the code?
for example
chem.inp:
C7H16 + 11O2=>7CO2 + 8H2O 5.00E+8 0.0 15780.0
chem.inp 15:
C7H16 + 11O2=>7CO2 + 8H2O 1.00E+8 0.0 15780.0
(5.00E+8 or 1.00E+8)
3-is there any other mistakes?
Thank you for your time and consideration
Saeid


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