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

unsteady DPM and steady flow

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

Like Tree1Likes
  • 1 Post By souria

Reply
 
LinkBack Thread Tools Display Modes
Old   August 18, 2010, 04:16
Default unsteady DPM and steady flow
  #1
Senior Member
 
Mohsin Mukhtar
Join Date: Mar 2010
Location: South Korea
Posts: 249
Rep Power: 8
Mohsin is on a distinguished road
I have unsteady DPM and steady flow but after 4000 iterations when solution converges. The particle fate is empty. I cant see any particle tracked. why it is so. Please explain.
Mohsin is offline   Reply With Quote

Old   August 18, 2010, 04:44
Default
  #2
Senior Member
 
xrs333
Join Date: Aug 2010
Posts: 125
Rep Power: 8
xrs333 is on a distinguished road
Hi,
Is the number that follows 'tracked=' reported in the console zero, too?
xrs333 is offline   Reply With Quote

Old   August 18, 2010, 04:45
Default
  #3
Senior Member
 
Mohsin Mukhtar
Join Date: Mar 2010
Location: South Korea
Posts: 249
Rep Power: 8
Mohsin is on a distinguished road
hi

No. its not. Its just not displaying any number. only writing fate and mass flux labels.

thanks
Mohsin is offline   Reply With Quote

Old   August 18, 2010, 05:09
Default
  #4
Senior Member
 
xrs333
Join Date: Aug 2010
Posts: 125
Rep Power: 8
xrs333 is on a distinguished road
Hi, Mohsin,
Have you set petinent start time and stop time for the injection?
xrs333 is offline   Reply With Quote

Old   August 18, 2010, 05:15
Default
  #5
Senior Member
 
Mohsin Mukhtar
Join Date: Mar 2010
Location: South Korea
Posts: 249
Rep Power: 8
Mohsin is on a distinguished road
It is steady state for the air flow but for DPM the particles will enter into the domain at t=8 seconds and will be injected until t=16 seconds. so i gave the particle strat andend time as 8 to 16 respetively.

The time step size was given as =0.5
and total number of time steps was=50

because the particles are large so i though to give the step size as 0.5 (which means after every 0.5 seconds the assigned number of particles will be injected) and the time period for the particles to stay in the domain was 5 seconds in steady case so 0.5/5=10 gives me the number of time steps for 1 period (i-e when the particles will move from inlet and captured at the outlet) so then i assumed 50 total number of time steps for my case so that i could simulate for 5 periods.

What could be wrong?
Mohsin is offline   Reply With Quote

Old   August 18, 2010, 05:22
Default
  #6
Senior Member
 
xrs333
Join Date: Aug 2010
Posts: 125
Rep Power: 8
xrs333 is on a distinguished road
I think all the particles injected during t=8~16s have escaped from the domain after some time steps of iteration.
xrs333 is offline   Reply With Quote

Old   October 9, 2014, 05:30
Default
  #7
Member
 
souria
Join Date: Mar 2013
Location: Nancy
Posts: 46
Rep Power: 4
souria is on a distinguished road
Hey Mohsin,
What did you call by "Period" here ?? And what does represent "5s" ? I m in the same case as you, and Im tryning to undersatnd the meaning of each parameters (number time step, particle time step size, start time, stop time..)
sharonyue likes this.
souria is offline   Reply With Quote

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Steady state DPM - Convergence and particle tracks Sandilya Garimella FLUENT 2 March 28, 2008 16:53
steady or unsteady DPM ??? Marina FLUENT 5 July 5, 2006 04:52
Unsteady DPM Johnny FLUENT 1 February 22, 2006 14:43
Steady State DPM K. Jagus FLUENT 7 June 24, 2005 17:10
steady or unsteady? (in dpm) winnie FLUENT 1 April 28, 2003 11:30


All times are GMT -4. The time now is 08:53.