CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > ANSYS > FLUENT > Fluent UDF and Scheme Programming

some problem about population balance model (DQMOM)

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

LinkBack Thread Tools Search this Thread Display Modes
Old   September 22, 2015, 06:31
Default some problem about population balance model (pbm,DQMOM)
New Member
Meng Liu
Join Date: Sep 2015
Posts: 14
Rep Power: 7
sola86 is on a distinguished road
When I used the population balance model (DQMOM) to simulate a two-phase flow (water and vapor) with UDF, some errors always appeared.

In steady simulations, the error message is "singular matrix". And in transient simulations, the error message is "unable to find rpvar 'pb/solve-interval'".

In fact, I don't konw how to set the VOF and m4 of the three second phases in BC. I only konw they need to be distanct from ansys help.

Do I have to choose "generate DQMOM vlaues from……"? What‘s the use of this step?

When I used QMOM to deal with the same case (transient), it can be calculated about 25 time steps. An error measage "ITMAX too small in gcfa too large" appeared. Then the calculation stopped with an error "floating point exception".

Did anyone ever met this problem?

Last edited by sola86; September 27, 2015 at 21:54.
sola86 is offline   Reply With Quote


dqmom, pbm, singular matrix, udf

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
Air-lift model with hot gases and water. Time step problem. PauliusRap FLOW-3D 0 August 4, 2014 05:47
problem with solving lagrange reaction cloud Polli OpenFOAM Running, Solving & CFD 0 April 30, 2014 08:53
population balance equation mdsvjpk FLUENT 0 February 13, 2012 01:28
Population Balance Model Tutorials sreepriyav FLUENT 2 January 20, 2011 06:00
Using population balance model payam_IUST FLUENT 0 December 6, 2010 02:12

All times are GMT -4. The time now is 04:02.