CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   OpenFOAM (http://www.cfd-online.com/Forums/openfoam/)
-   -   dieselSpray problem (http://www.cfd-online.com/Forums/openfoam/82823-dieselspray-problem.html)

JanKubata December 7, 2010 04:49

dieselSpray problem
 
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?

Rickard.Solsjo December 7, 2010 10:32

..too little info.
What evaporation model are you using? What is the initial temperature and what is the injection temperature?

JanKubata December 7, 2010 10:42

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.

Rickard.Solsjo December 7, 2010 10:47

what about the injectorproperties?

JanKubata December 7, 2010 10:55

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)
);

Rickard.Solsjo December 7, 2010 11:01

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?)

JanKubata December 7, 2010 11:10

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.


All times are GMT -4. The time now is 09:03.