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

Questions on DPM model..please

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   October 6, 2010, 04:16
Default Questions on DPM model..please
  #1
Member
 
Panos
Join Date: Nov 2009
Posts: 33
Rep Power: 17
panos_metal is on a distinguished road
Goodmorning

Im simulating the flow of air in a channel coupled with heat transfer from the walls to the air stream. Now i would like to insert a mass flow. The volume fraction is les than 0.01 Vsolid/Vair so i selected the DPM model. Its the first time im using this model so i wanna ask about the convergency or any strategies to have a solution. How can i check the solution of the DPM?
In addition i would like to activate the walls radiation. In the previous simulations (without solid particles) i assumed air as transparent media so radiation didnt effect the results (standard wall temperature). No radiation will effect the solids temperature. I was thinking of activating radiation after i simulate the solids movement. Is this right? Do you agree that S2S radiation model is good for my case or maybe DO model?

Thank you in advance
panos_metal is offline   Reply With Quote

Old   October 6, 2010, 12:01
Default
  #2
New Member
 
sreenivasa rao gubba
Join Date: Sep 2010
Location: Leeds University, UK
Posts: 28
Rep Power: 16
sreerao is on a distinguished road
Hi

what type of solid particle are they? such as inert or reacting etc. If they are inert, I would not think radiation will have much impact on them and viceversa. However, if the particles are reacting, you need to think of radiation aprior to DPM.

You can get postprocess DPM from reports. If you tell me what you exactly looking for, I may shed more light on it.

Sree
sreerao is offline   Reply With Quote

Old   October 6, 2010, 15:44
Default
  #3
Member
 
Panos
Join Date: Nov 2009
Posts: 33
Rep Power: 17
panos_metal is on a distinguished road
Hello Sree and thank you for your interest

My particles are inert..lets say its sand. i have no reaction but only heat of the particles. I wanted to know the temperature ,velocity and the residence time of the particles in the tube . I wanted to add radiation because in some cases there is high difference between air and walls temperature (when flow is high). In this case , due to radiation it is expected that particles will raise the air temperature.

If i wanna couple the wall radiation effect , it would be better to do it before solving the DPM?
What would you recommend me

Thank you in advance
panos_metal is offline   Reply With Quote

Old   October 7, 2010, 07:26
Default
  #4
New Member
 
sreenivasa rao gubba
Join Date: Sep 2010
Location: Leeds University, UK
Posts: 28
Rep Power: 16
sreerao is on a distinguished road
Hi

Yes, you need to do your radiation first for this case. Once you have decent convergence, you can initiate DPM in "Graphics & Animatons>particle tracks>particle variables" if it is one-way coupling. If you are considering two-way coupling, you need to set when the injections will release in "models>discrete phase" by choosing after how many continuous iterations do you want to inject the particles.

If you think even your inert particles does effect (adding energy source trhough radiation) continuous phase, then you should choose two-way coupling. Otherwise, it is not really nessasary.

Just check wether you can switch on or not "Particle Radiation Interactions" in DPM for inert particles or not. If it lets you to switch, that would take care of the effect radiation.

Hope this helps.
Sree
sreerao is offline   Reply With Quote

Reply

Tags
convergence, discrete phase model, s2s radiatiation model


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
Use of k-epsilon and k-omega Models Jade M Main CFD Forum 40 January 27, 2023 08:18
So many questions in DPM & UDF - Help! URGENT! Prashanth FLUENT 0 March 3, 2009 23:26
Questions about Residual tolerance and EBU model Mehdi Siemens 0 April 6, 2006 10:23
questions about keps model and wall function sarah_ron FLUENT 3 October 15, 2004 08:50
About DPM model Andy li FLUENT 0 September 19, 2004 05:10


All times are GMT -4. The time now is 12:48.