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

slow after mesh for enhanced wall treat DPM

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

Reply
 
LinkBack Thread Tools Display Modes
Old   May 1, 2007, 17:20
Default slow after mesh for enhanced wall treat DPM
  #1
joshkemp
Guest
 
Posts: n/a
I ran my original case using realizable k-epsilon with non-equilibrium wall function with about 900k cells. Then I used the DPM model to add spray to the domain and the discrete phase iterations took a few more hours to run .

Then I realized my wall y+ values were all too low and it was going to be too hard to try to get the cells large enough to be above Y+ of 30, so I decided to switch to enhanced wall treatment with all y+ values less than 1. The resulting mesh was again around 900k cells. I ran the new mesh again and had no problems getting convergence on the airflow. Then I turned on the DPM model again and tried to iterate for the spray. I let it run about 24 hrs and it still had not finished one DPM iteration.

I am confused as to why it the DPM iteration is taking so long. Like I said, the mesh is about the same size and both cases use exactly the same DPM setup. I am reading the same initial distribution in from file. Both cases were ran on the same 20 node computing cluster. The airflow on the new mesh did not take any longer to converge than the original mesh. All of the cells are large enough so that the largest droplet will not occupy more than 10% of the volume.

Any Ideas?
  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
how to set periodic boundary conditions Ganesh FLUENT 13 January 22, 2014 05:11
Mesh motion with Translation & Rotation Doginal CFX 2 January 12, 2014 07:21
Mesh independence issues with wall shear stress jw22 STAR-CCM+ 1 July 10, 2011 06:21
snappyHexMesh won't work - zeros everywhere! sc298 OpenFOAM Native Meshers: snappyHexMesh and Others 2 March 27, 2011 21:11
the near wall function and the mesh feixiangniao CFX 1 April 30, 2010 06:43


All times are GMT -4. The time now is 22:28.