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

Troubles with the dpm model

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 23, 2009, 09:36
Default Troubles with the dpm model
  #1
Marco Antonelli
Guest
 
Posts: n/a
Hi, I'm Marco Antonelli and I am researcher at the University of Pisa.

I set up a cluster for parallel computing using Fluent 6.3 and I'm simulating the injection of gasoline inside an engine cylinder. When I used a single pc it ran all ok, but since I've been trying using this cluster, I've this trouble with the injection: after some time steps, the calculation is blocked at the dpm injection advance and does nor proceed, neither giving any error.

Anyone had the same trouble than me?

Thanks

Marco
  Reply With Quote

Old   February 24, 2009, 16:40
Default Re: Troubles with the dpm model
  #2
John S.
Guest
 
Posts: n/a
Are you running a multiphase simulation?
  Reply With Quote

Old   February 25, 2009, 03:37
Default Re: Troubles with the dpm model
  #3
Marco Antonelli
Guest
 
Posts: n/a
My simulation is a discrete phase one. I'm injecting gasoline inside an engine cylinder.

  Reply With Quote

Old   February 25, 2009, 12:23
Default Re: Troubles with the dpm model
  #4
John S.
Guest
 
Posts: n/a
The reason I asked, to quote the 6.2 manaul..

"When tracking particles in parallel, the DPM model cannot be used with any of the multiphase flow models (VOF, mixture, or Eulerian { see Chapter 23: Modeling Multiphase Flows) if the shared memory option is enabled (Section 22.11.9: Parallel Processing for the Discrete Phase Model). (Note that using the message passing option, when running in parallel, enables the compatibility of all multiphase ow models with the DPM model.)"
  Reply With Quote

Old   February 26, 2009, 03:29
Default Re: Troubles with the dpm model
  #5
Marco Antonelli
Guest
 
Posts: n/a
No, any of these model was used. Moreover, the message passing option is currently used. The strange fact is that the calculation start, but stops after a random number of time steps without an apparently cause.

bye

Marco
  Reply With Quote

Old   February 28, 2009, 20:08
Default Re: Troubles with the dpm model
  #6
giovanni franchello
Guest
 
Posts: n/a
Do you use wall-film model ? The same happens also to me
  Reply With Quote

Old   March 3, 2009, 10:24
Default Re: Troubles with the dpm model
  #7
Marco Antonelli
Guest
 
Posts: n/a
Yes, I do. I'm trying to change some parameters about numerics, but I've still got very few results...

If I'll discover something interesting, I'll post it.

bye

Marco
  Reply With Quote

Old   March 3, 2009, 12:12
Default Re: Troubles with the dpm model: collision probl ?
  #8
Gian
Guest
 
Posts: n/a
I am simulating injection of liquid ammonia (tb=-33 Deg) in tha atmosphere (air + water vapour, 80% humidity). The solver is pressure-based, usteady. Problem time 900 sec, time step=0.25 sec, 150000 cells, 6 node parallel computer. DPM: injected 5 parcels per particle time step=0.05 sec. coupled, unsteady. Boundary: wall-film. I had very big problems: temperature & pressure out of the limits, dpm concentration > 10000kg/m3, extreme jumps in the mass sources, evaporation of droplets with temp. below dew point (??), crash. Despite I eliminate problems in crashes (re-writing the mass & heat transfer routines), FLUENT enters in an infinite loops after the message Advancing DPM Injection ...

I remove the problem by switching off the droplet-collision option !!!

Try it. Gian

PS: now I use wall-jet because with wall-film I had problems in parallel processing like "lost x particles in node y" and consequent mass error

  Reply With Quote

Old   March 3, 2009, 12:55
Default Re: Troubles with the dpm model: collision probl ?
  #9
Marco Antonelli
Guest
 
Posts: n/a
However, coalescence is a very important matter while simulating injections (especially gasoline injection)...
  Reply With Quote

Old   June 14, 2010, 04:48
Default
  #10
New Member
 
Shao Senlin
Join Date: Jun 2010
Posts: 1
Rep Power: 0
shaosenlin is on a distinguished road
I have the same qusetion, how did you solve it?
think you!
shaosenlin is offline   Reply With Quote

Old   December 7, 2010, 10:18
Default
  #11
Member
 
Marta's Avatar
 
Marta Lazzarin
Join Date: Jun 2009
Location: Italy
Posts: 71
Rep Power: 16
Marta is on a distinguished road
Hi All! Is the wall-film model compatible with combustion models in Fluent?

Thanks a lot in advance!

Marta
Marta 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 troubles Rachel FLUENT 1 June 30, 2008 00:02
AMG troubles - help? Stephanie Siemens 1 September 22, 2007 15:03
3d VOF troubles... Mac FLUENT 0 March 12, 2007 09:41
LAMMPI troubles mer OpenFOAM Installation 4 September 13, 2005 06:41
some video troubles... giosue Siemens 2 February 19, 2003 11:03


All times are GMT -4. The time now is 11:50.