CFD Online Logo CFD Online URL
Home > Forums > FLUENT

Ever wondered abt this?-About transient DPM

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

LinkBack Thread Tools Display Modes
Old   August 8, 2002, 13:47
Default Ever wondered abt this?-About transient DPM
Posts: n/a

I was to model transient simulation on particles realised in a room from the same location from start time t=2 sec to t=4sec.

My supervisor suddenly ask me this question, "If under steady airflow velocity condition in the room,the particle(s) released at time t=4 should follow the same trajectory path as the particle(s)released at time t=2 if it/they are injected at the SAME location."

Hence if u are able to trace the paths of 5 particles released at time t=2, and if at time t=4,another 5 particles are released all at the SAME locations of the previous 5, although there may be 10 particles in the room at t>4sec, there should be strictly only 5 trajctory pathlines since the velocity profile in the room is at steady state.

1.What he said does sound reasonable. Does anyone agree/disagree with what he said? If he is not correct, why?

2.Also, since under transient, when we click on display, it shows the current positions of the partciles, and we cant do a path tracking display. I was thinking to find out if his claim is correct, I will have to monitor the position displacement values of two particles released at different timings and see if the particle released later follows the same position displacement with the earlier particle. Does anyone has a better way to investigate?

Also, anyone has thought and experiment on the above thoughts, PLEASE let me know how are your results so that I can double check it against mine..

  Reply With Quote

Old   September 3, 2002, 11:20
Default Re: Ever wondered abt this?-About transient DPM
Posts: n/a

I can add some light to this issue. You might want to consider along these lines: When you are doing particle tracking, did you assume a "one-way or two way coupling"? If it is one way coupling, then I take the side of your supervisor. If it is a two-way(or a 4 way) coupling, unless there are some specific reasons(for ex. if your particle size and/or density is too small) then I would say the particle tracks will most certainly be different.

Hope this will add up to your thoughts.

Regards, Sridhar.
  Reply With Quote


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
Transient conduction possible in fluent? jlefevre76 FLUENT 2 February 5, 2013 10:53
DPM in transient analysis g0800276 FLUENT 0 September 8, 2011 22:03
DPM transient laminar flow over a cylinder JSoares FLUENT 1 April 12, 2011 02:37
Transient DPM initial properties Spurny Fluent UDF and Scheme Programming 0 January 28, 2011 02:39
Best practice for transient simulations? siw CFX 5 October 30, 2010 05:45

All times are GMT -4. The time now is 03:58.