CFD Online URL
[Sponsors]
Home > Forums > CFX

boundary conditions for cyclone separator

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

Reply
 
LinkBack Thread Tools Display Modes
Old   June 11, 2010, 03:27
Default boundary conditions for cyclone separator
  #1
New Member
 
siddharth
Join Date: Jun 2010
Posts: 7
Rep Power: 6
siddhukb is on a distinguished road
i am doing a gas-solid simulation of cyclone separator. In the solution i get the mass is not balanced.
i have attached pics of the domain settings.
can someone help me in showing where i went wrong or what is the correct settings?

i have given a velocity inlet with both air and aluminium having 10m/s and air is 0.9 and aluminium is 0.1 volume fraction
both overflow and underflow i have given pressure outlet with pressure of 0atm
1.jpg

2.JPG

3.JPG

4.JPG
siddhukb is offline   Reply With Quote

Old   June 14, 2010, 19:20
Default
  #2
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 9,859
Rep Power: 78
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
Please show your convergence results, and maybe post the CCL file.
ghorrocks is offline   Reply With Quote

Old   June 15, 2010, 04:07
Default
  #3
New Member
 
siddharth
Join Date: Jun 2010
Posts: 7
Rep Power: 6
siddhukb is on a distinguished road
i have attached the ccl file

Thanks in advance
siddharth

-----------------------------
cyclone_multiphase_v5_1.zip
siddhukb is offline   Reply With Quote

Old   June 15, 2010, 07:53
Default
  #4
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 9,859
Rep Power: 78
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
You are using a Reynolds Stress turbulence model. If you go to SST or some other more stable turbulence scheme it will be much more stable.
ghorrocks is offline   Reply With Quote

Old   June 15, 2010, 08:11
Default
  #5
New Member
 
siddharth
Join Date: Jun 2010
Posts: 7
Rep Power: 6
siddhukb is on a distinguished road
but most of the journal i had studied suggested that Reynolds stress turbulence model is most suitable for cyclone separator


Thanks
siddharth
siddhukb is offline   Reply With Quote

Old   June 15, 2010, 08:18
Default
  #6
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 9,859
Rep Power: 78
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
It is, but it will make convergence extremely difficult.

Get the basic model working with SST. Once everything is working with SST then switch back to RSM.

Also keep in mind that multiphase modelling introduces large simplifications. These simplifications can swamp the extra accuracy gained by RSM models. So if you have a have heavy multiphase interaction then I probably would not bother with RSM at all.
ghorrocks is offline   Reply With Quote

Old   June 15, 2010, 08:53
Default
  #7
New Member
 
siddharth
Join Date: Jun 2010
Posts: 7
Rep Power: 6
siddhukb is on a distinguished road
will look into it.
I have one more doubt.
In the basic settings of the Domain -- Air is the continuous fluid. what should i define aluminium? cause i am confused in giving it as continuous fluid or dispersed solid or particle transport solid.

Thanks
siddharth
siddhukb is offline   Reply With Quote

Old   June 15, 2010, 09:01
Default
  #8
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 9,859
Rep Power: 78
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
For a full answer to that question do a multiphase modelling course.

The quick answer is - light particle loadings - use particle tracking, heavy particle loadings use a Eularian approach.
ghorrocks is offline   Reply With Quote

Reply

Tags
cfx, cyclones separator

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
Impinging Jet Boundary Conditions Anindya Main CFD Forum 24 January 11, 2012 14:40
boundary conditions and mesh exporting vaina74 Open Source Meshers: Gmsh, Netgen, CGNS, ... 2 May 27, 2010 10:38
Pressure boundary conditions Lionel S. Main CFD Forum 1 August 24, 2007 19:03
Trimmed cell and embedded refinement mesh conversion issues michele OpenFOAM Other Meshers: ICEM, Star, Ansys, Pointwise, GridPro, Ansa, ... 2 July 15, 2005 05:15
A problem about setting boundary conditions lyang Main CFD Forum 0 September 19, 1999 19:29


All times are GMT -4. The time now is 05:31.