CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > Siemens > STAR-CCM+

Volume Fraction Scene Initialisation

Register Blogs Community New Posts Updated Threads Search

Like Tree1Likes
  • 1 Post By LuckyTran

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 13, 2021, 06:21
Default Volume Fraction Scene Initialisation
  #1
New Member
 
Join Date: Mar 2021
Posts: 2
Rep Power: 0
jp2617 is on a distinguished road
Hi there!

Apologies if this was addressed in another thread - I haven't found anyone facing a similar issue.

I'd like to initialise an oil volume fraction scene of a disc and a gear immersed into oil within two separate simulations. I have successfully initialised the oil volume fraction scene for the disc, but not the gear. Could you please help me get the two colour- to represent the two-phases (oil below and air above) - appearance in the scene for the case of the gear as you see for the disc in the image attached - VOF_disc?

I have defined within the 'Volume Fraction' initial conditions segment, a field function for the initial volume fraction of the oil. The formula I used is ($$Centroid[1]<=-0.023?1:0) as recommended in minute 8:35 of the following video:- https://www.youtube.com/watch?v=qKUU5l1BmDA. I have also followed the exact procedure of this video to set up the volume fraction, with exception of changing the [2] in the above field function to [1] to reflect a difference in the coordinate directions.

In the case of the gear, both the scale for the oil volume fraction and colour of the scene does not change in value or colour respectively, in response to any changes in the definition of the -0.023 value - the immersion depth defined from the y-midspan downwards - in the mentioned field function. The scale of the oil volume fraction here maintains a value of 0.0 on either end always.

Funnily enough, when I define the initial condition of the oil volume fraction as a constant instead, with a value of 0.5, the upper and lower bounds of the scale change in its values to 0.5, but the scene colour remains unchanged (all-blue) when the scene is initialised (see attached image, VOF_Gear). I am happy to privately share my model with you if you dropped me an email:- jesidhn@gmail.com.

Thanks so much!
Attached Images
File Type: png VOF_disc.PNG (16.8 KB, 11 views)
File Type: png VOF_Gear.PNG (13.5 KB, 13 views)
jp2617 is offline   Reply With Quote

Old   May 13, 2021, 11:04
Default
  #2
Senior Member
 
Lucky
Join Date: Apr 2011
Location: Orlando, FL USA
Posts: 5,676
Rep Power: 66
LuckyTran has a spectacular aura aboutLuckyTran has a spectacular aura aboutLuckyTran has a spectacular aura about
[0] is the x-coordinate, [1] is the y-coordinate and [2] is the z-coordinate. Your image is on the xy-plane so it would make sense that it is constant on this plane if you used position[2] as a threshold in your field function definition.
jp2617 likes this.
LuckyTran is offline   Reply With Quote

Old   May 13, 2021, 11:53
Default
  #3
New Member
 
Join Date: Mar 2021
Posts: 2
Rep Power: 0
jp2617 is on a distinguished road
Thanks for the reply. The immersion depth varies in the y-direction however, corresponding to position [1]. This works for the case of the disc.
jp2617 is offline   Reply With Quote

Old   May 13, 2021, 18:02
Default
  #4
Senior Member
 
Lucky
Join Date: Apr 2011
Location: Orlando, FL USA
Posts: 5,676
Rep Power: 66
LuckyTran has a spectacular aura aboutLuckyTran has a spectacular aura aboutLuckyTran has a spectacular aura about
Try plotting the y-position. You might have your gear placed in a location where you think it is not.
LuckyTran 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
multiphaseEulerFoam (OF2.3.0) : Courant number explodes when running in parallel Mehrez OpenFOAM Running, Solving & CFD 10 May 18, 2016 11:44
Stuck in a Rut- interDyMFoam! xoitx OpenFOAM Running, Solving & CFD 14 March 25, 2016 07:09
mpirun interFoam very stable --> then blows up ghadab OpenFOAM Running, Solving & CFD 3 October 27, 2013 10:34
air bubble is disappear increasing time using vof xujjun CFX 9 June 9, 2009 07:59
the Eulerian model and the lower volume fraction hx li FLUENT 2 October 27, 2005 06:17


All times are GMT -4. The time now is 07:00.