CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > ANSYS > FLUENT

Discrete Phase Modelling in Fluent

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

LinkBack Thread Tools Search this Thread Display Modes
Old   February 18, 2015, 10:36
Default Discrete Phase Modelling in Fluent
New Member
Ravinder Gill
Join Date: Sep 2014
Location: Windsor,ON
Posts: 19
Rep Power: 9
gill11a is on a distinguished road
I have some general questions about DPM in Fluent.
1)How does Fluent estimate the trajectories of particles if you enable the 'interaction with continuous phase' or disable it? What is the difference in two?
2) Is it possible to export the forces acting on a particle? I have looked into it and i could not figure it out. However, i was able to export the velocity magnitude as a function of particle's trajectory.

Thanks in advance.
gill11a is offline   Reply With Quote

Old   February 18, 2015, 13:51
Senior Member
Cees Haringa
Join Date: May 2013
Location: Delft
Posts: 607
Rep Power: 0
CeesH is on a distinguished road
Hi gill;

1) if you disable interaction with continuous phase, the coupling is 1-way. That means the particle trajectory is influenced by forces acting on the particle from the fluid, but the fluid flow is not influenced by the particles. FLUENT integrates the force balance on the particle; the integration routine is chosen depending on you own settings.

If you enable interaction, the fluid flow is influenced by the momentum of the particles as well. Within a timestep, the fluid trajectory is solved, then the particle trajectory based on that fluid flow. The fluid flow is then updated, based on the particle motions, and afterwards the particle positions are recalculated, on and on until the situation converged within the set residuals.

2) I don't know any way to directly output the forces acting on the particle. You could write a UDF to output this - basically, you need UDF that does the same calculation as FLUENT does, and outputs it to a file.
CeesH is offline   Reply With Quote

Old   March 8, 2015, 18:56
Default DPM problem
New Member
Join Date: Oct 2014
Posts: 21
Rep Power: 9
apo is on a distinguished road
Hi all, iam working on a boiler problem and I am using group injection. My combusting material is coal mv, I am using combusting at material type and the devolatilizing species are mv_vol. The vaporization Temperature of the combusting material is 400K. When I use at injection initial Temperature T=400K, it's all ok, but when I use initial Temperature T=300K I have many problems, such as "Temperature limited to 1 or to 5000K. Is it wrong to have initial Temperature less than Vaporization Temperature?

Thanks in advance,
apo is offline   Reply With Quote


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
Discrete Phase model hari_ls FLUENT 2 December 4, 2010 06:30
continuous and discrete phase coupling in fluids-HELP atmcfd Main CFD Forum 1 December 30, 2009 23:02
fluent multiphase modelling thinktank FLUENT 0 November 28, 2009 13:41
Discrete phase model in porous media Pradeep FLUENT 0 February 3, 2006 16:30
discrete phase in turbulent flow using fluent ursenbacher Main CFD Forum 0 January 5, 1999 11:25

All times are GMT -4. The time now is 12:36.