CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM

dieselSpray problem

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 7, 2010, 03:49
Default dieselSpray problem
  #1
New Member
 
Jan Kubata
Join Date: Mar 2009
Location: Prague, Czech Republic
Posts: 10
Rep Power: 17
JanKubata is on a distinguished road
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?
JanKubata is offline   Reply With Quote

Old   December 7, 2010, 09:32
Default
  #2
Senior Member
 
Rickard
Join Date: May 2010
Location: Lund, Skåne, Sweden
Posts: 143
Rep Power: 15
Rickard.Solsjo is on a distinguished road
..too little info.
What evaporation model are you using? What is the initial temperature and what is the injection temperature?
Rickard.Solsjo is offline   Reply With Quote

Old   December 7, 2010, 09:42
Default
  #3
New Member
 
Jan Kubata
Join Date: Mar 2009
Location: Prague, Czech Republic
Posts: 10
Rep Power: 17
JanKubata is on a distinguished road
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.
JanKubata is offline   Reply With Quote

Old   December 7, 2010, 09:47
Default
  #4
Senior Member
 
Rickard
Join Date: May 2010
Location: Lund, Skåne, Sweden
Posts: 143
Rep Power: 15
Rickard.Solsjo is on a distinguished road
what about the injectorproperties?
Rickard.Solsjo is offline   Reply With Quote

Old   December 7, 2010, 09:55
Default
  #5
New Member
 
Jan Kubata
Join Date: Mar 2009
Location: Prague, Czech Republic
Posts: 10
Rep Power: 17
JanKubata is on a distinguished road
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)
);
JanKubata is offline   Reply With Quote

Old   December 7, 2010, 10:01
Default
  #6
Senior Member
 
Rickard
Join Date: May 2010
Location: Lund, Skåne, Sweden
Posts: 143
Rep Power: 15
Rickard.Solsjo is on a distinguished road
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?)
Rickard.Solsjo is offline   Reply With Quote

Old   December 7, 2010, 10:10
Default
  #7
New Member
 
Jan Kubata
Join Date: Mar 2009
Location: Prague, Czech Republic
Posts: 10
Rep Power: 17
JanKubata is on a distinguished road
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.
JanKubata is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
UDF compiling problem Wouter Fluent UDF and Scheme Programming 6 June 6, 2012 04:43
Incoherent problem table in hollow-fiber spinning Gianni FLUENT 0 April 5, 2008 10:33
natural convection problem for a CHT problem Se-Hee CFX 2 June 10, 2007 06:29
Adiabatic and Rotating wall (Convection problem) ParodDav CFX 5 April 29, 2007 19:13
Is this problem well posed? Thomas P. Abraham Main CFD Forum 5 September 8, 1999 14:52


All times are GMT -4. The time now is 07:35.