CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > CFX

problem with dispersed solid model and exp

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   October 4, 2016, 00:09
Question problem with dispersed solid model and exp
  #1
New Member
 
Join Date: Nov 2014
Posts: 18
Rep Power: 12
Ludwig Prandtl is on a distinguished road
hi
I'm modeling a tank that contain water and some solid particles. I'm using dispersed solid model to simulate solid particles. i want to record the volume fraction or mass concentration of particles at outlet. so i used the following exp:

ave(phase1.vf )@outlet

after some time...the tank is empty of solid particles but the exp give some bad result and it shows that solids are crossing the outlet but there is no solid in tank (
I did simulation with very qualified mesh but it happened again.i used dp but not helped...

can anyboidy help me whats wrong with this expression ?
i think the exp is wrong...please give me some ideas.

thanks
Ludwig Prandtl is offline   Reply With Quote

Old   October 4, 2016, 05:51
Default
  #2
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,870
Rep Power: 144
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
Note the averaging function you used is just an arithmetic average of all the faces, regardless of size. You probably want to use areaAve() instead so you get an area weighted average.

But I cannot help you with your actual question at the moment. It sounds like a setup problem.
ghorrocks is offline   Reply With Quote

Old   October 6, 2016, 12:23
Default
  #3
New Member
 
Join Date: Nov 2014
Posts: 18
Rep Power: 12
Ludwig Prandtl is on a distinguished road
Quote:
Originally Posted by ghorrocks View Post
Note the averaging function you used is just an arithmetic average of all the faces, regardless of size. You probably want to use areaAve() instead so you get an area weighted average.

But I cannot help you with your actual question at the moment. It sounds like a setup problem.

Hi ghorrocks. thank you
i also used areaAve() and the results were same..now I use massflowAve() and i'm waiting for the results...

some information of simulation:
particle diameter : 30 micron
particle density :1900 kg m^-3
using buoyancy
turbulence model: k-e RNG (Homo)
isothermal
drag coef: 0.44 (default)
BC: 1 inlet-1 outlet-2 symmetric-walls..

and something that make me confused in results : for the walls..the contour show a 0.5 volume fraction for solid just at one point on wall (after the whole particle left the tank) ..I used very very refined mesh with inflation...max of yplus is 3
...
Ludwig Prandtl is offline   Reply With Quote

Old   October 9, 2016, 08:04
Default
  #4
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,870
Rep Power: 144
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
Is this a Eularian or Lagrangian model?

Please shows some images of what you are modelling and the results you are getting. Also show why it is wrong, and what you expect to get.
ghorrocks is offline   Reply With Quote

Reply


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
Eulerian-Granular Mass transfer UDF problem therandomestname FLUENT 1 April 25, 2011 18:58
Regarding Implementation of Hershel Bulkley Model in Viscosity correlation Pathak FLOW-3D 0 August 24, 2009 07:34


All times are GMT -4. The time now is 16:12.