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Old   December 7, 2010, 04:49
Default dieselSpray problem
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Jan Kubata
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I have a problem with modeling of diesel spray. I have few cases with almost same geometry, but with different number of cells - 0.5M, 0.87M and 3M. Initial conditions are same for all cases.
If I'm using dieselFoam for the smallest case it run without problems and spray normally evaporates. For the "medium" case it's still evaporates, but the Evaporation continuity error is almost 10%

Injected liquid mass........... | 1.97817 mg
Liquid Mass in system.......... | 1.53407 mg
SMD, Dmax...................... | 38.6388 mu, 99.2837 mu
Added gas mass................. | 0.490854 mg
Evaporation Continuity Error... | 0.0467523 mg

For the biggest case - there is no evaporation.

Injected liquid mass........... | 36.8222 mg
Liquid Mass in system.......... | 36.8222 mg
SMD, Dmax...................... | 50.4857 mu, 99.9787 mu
Added gas mass................. | 32.1204 mg
Evaporation Continuity Error... | 32.1204 mg

I don't uderstand where is the problem, could anybody help me?
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Old   December 7, 2010, 10:32
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Rickard
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..too little info.
What evaporation model are you using? What is the initial temperature and what is the injection temperature?
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Old   December 7, 2010, 10:42
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Jan Kubata
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I'm using this setup:
atomizationModel blobsSheetAtomization;
includeOscillation on;
breakupModel ReitzKHRT;
injectorModel hollowConeInjector;
collisionModel trajectory;
evaporationModel standardEvaporationModel;
heatTransferModel RanzMarshall;
dispersionModel off
dragModel standardDragModel;
wallModel reflect;

Fuel injection temperature is 300K and initial temperature inside geometry is 1500K.
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Old   December 7, 2010, 10:47
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Rickard
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what about the injectorproperties?
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Old   December 7, 2010, 10:55
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definedInjectorProps
{
position ( -0.0003 0.0491 -0.0271386 );
direction ( -1 0 0 );
diameter 0.45e-3;
mass 0.002939;
temperature 300;
nParcels 4000000;
X
(
1
);
massFlowRateProfile
(
(0.0 1.0)
(1.0 1.0)
);
velocityProfile
(
( 0.0 13)
( 1.0 13)
);
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Old   December 7, 2010, 11:01
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I have difficulties to visualize your mesh, are you sure you are injecting in the correct direction and in the center of your injection plane (if that is what you want to do?)
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Old   December 7, 2010, 11:10
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Jan Kubata
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I'm simulating something like burner - injector is in the center of one side and outflow is on oposite one. The position of injector is ok, because with smaller number of cells with same geometry I have no problems.
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