# dpm modeling

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

 December 3, 2012, 05:12 dpm modeling #1 New Member   milad Join Date: Oct 2012 Posts: 2 Rep Power: 0 hi what is difference between steady particle tracking and unsteady particle tracking?

 December 3, 2012, 08:22 #2 Member   barzin Join Date: Jan 2011 Posts: 33 Rep Power: 6 Hi Milad, Well the difference is the same as the difference between steady state solution and transient solution. In Steady particle tracking the entire particle trajectory is computed until the solution gets converged. More mathematically, the Lagrangian trajectory integration time is from t=0 to t=inf. However in unsteady particle tracking, the Lagrangian integration time is between the assign values (say t=0 to 1e-06 and so on). Hope that helps kamyab likes this.

 December 5, 2012, 12:34 #3 New Member   milad Join Date: Oct 2012 Posts: 2 Rep Power: 0 Hi Barzin thanks a lot. I don't understand. I think that in steady particle tracking derivative time is zero so means d/dt=0 therefore velocity is constant and it's meaningless because of Lagrangian approah is always unsteady. so why dpm modeling in fluent has steady particle tracking? I don't understand this contradiction. please explain it.:(:(

 December 6, 2012, 05:25 #4 Member   barzin Join Date: Jan 2011 Posts: 33 Rep Power: 6 Milad jan Why do you think it's meaningless? plus it doesn't mean that particle velocity is constant through out the trajectory. imagine that you solve a continuous flow in a pipe. In steady calculation if the initial velocity at inlet is constant, the velocity will decay along the pipe. I think you can adapt this to a particle trajectory calculation.

 December 7, 2012, 08:57 #5 New Member     Y. Yang Join Date: Mar 2010 Location: Miami, United States Posts: 27 Rep Power: 7 His Barzin, I have a question too, assume that in a unseady problem, in the steady particle tracking, only the entire particle trajectory is computed until the end of the calculation ? that does not make sense

 December 7, 2012, 12:29 #6 Member   barzin Join Date: Jan 2011 Posts: 33 Rep Power: 6 Hi mate, Sorry I did not get the question. Can u please shed more light?

 December 8, 2012, 05:33 #7 New Member     Y. Yang Join Date: Mar 2010 Location: Miami, United States Posts: 27 Rep Power: 7 I am sorry for that. What I dont understand is that "Lagrangian trajectory integration time is from t=0 to t=inf"?

 December 8, 2012, 07:05 #8 Member   barzin Join Date: Jan 2011 Posts: 33 Rep Power: 6 Don't worry, I got you now, This mean the whole particle trajectory!

 January 23, 2013, 07:00 Dpm #9 Member   payamfadaei Join Date: Oct 2012 Location: Mashhad/Iran Posts: 32 Rep Power: 4 Hi Dears I have a air flow which enter a cavity and exit it,I want to add some particles to the flow which has a lift and drag(I'm going to change their direction by magnetic fields)...How can I determine the diam and number of particles,velocity,permaebility and density and.... In which panel this settings exist?? Thanks a lot

 January 28, 2013, 11:01 #10 Member   barzin Join Date: Jan 2011 Posts: 33 Rep Power: 6 Hey Payam, You need to have a deeper look in DPM and injection panel! I'm sure you'll able to find it.

January 29, 2013, 07:33
Dpm
#11
Member

Join Date: Oct 2012
Posts: 32
Rep Power: 4
Quote:
 Originally Posted by barzin Hey Payam, You need to have a deeper look in DPM and injection panel! I'm sure you'll able to find it.
But when I change the air by Water it doesn't work.My problem is "Fe" particles which is immersed in Water.But I'm not sure that Dpm is the model I should use!

Thanks

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post Amit Katiyar FLUENT 4 November 21, 2014 06:21 harry king FLUENT 1 May 6, 2012 22:11 bashu FLUENT 0 October 4, 2010 12:00 Mohsin FLUENT 0 March 31, 2010 22:11 Bob Stanislawsky FLUENT 0 June 18, 2002 10:07

All times are GMT -4. The time now is 12:42.