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

level set

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 20, 2004, 15:27
Default level set
  #1
jinfeng
Guest
 
Posts: n/a
I'm working on simulation of bubble by using LSM. To solve level set function, centered difference scheme or ENO can be used to discretize the convection term (according to Chang, et al 124, 449-464, JCP, 1996). But in my case, the results are pretty different, could any one give suggestion to determine which way is more realistic?

My thought is that if I refine the grids, the scheme leading to small different results is more realistic, does this more sense?

Thanks for your attention!

Wu
  Reply With Quote

Old   September 20, 2004, 17:26
Default Re: level set
  #2
Junseok Kim
Guest
 
Posts: n/a
most of cases, ENO is better than centeral scheme when dealing with convection terms.

  Reply With Quote

Old   September 20, 2004, 17:46
Default Re: level set
  #3
jinfeng
Guest
 
Posts: n/a
Thanks, when I use central scheme, the bubble grows, then shrink, then grows (oscillation duo to evaporation and condensation). After refine, these oscillation disappear.

If using ENO, no oscillation comes out. The problem is that in reality, oscillation may appear.
  Reply With Quote

Old   September 20, 2004, 17:55
Default Re: level set
  #4
Junseok Kim
Guest
 
Posts: n/a
Bubble oscillation should come from surface tension, not from the convection discretization scheme.
  Reply With Quote

Old   September 20, 2004, 19:07
Default Re: level set
  #5
jinfeng
Guest
 
Posts: n/a
Sorry for not making myself clear. In my case, the bubble is put at the heating surface. The oscillation mentioned is referred to the shrinking and expanding of the bubble base, the change of the bubble volume is related to heat transfer. Using ENO scheme didn't show the base oscillation. What I want to know is if the different schemes of convection term may give different topology.
  Reply With Quote

Old   September 20, 2004, 19:19
Default Re: level set
  #6
Junseok Kim
Guest
 
Posts: n/a
Unfornately, it does change the toplogy with different convection scheme. Especially, some critical situation such as pinch-off and dramatic topological transitions, but in lot of cases, those could be generated by overall numerical code, so you'd better test yours with established test problems first.

  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
Set liquid level in a Tank chemeng OpenFOAM 4 April 7, 2010 00:46
calculating Normal vector in level set method amir2920 Main CFD Forum 1 July 21, 2009 08:25
Reinitialization for level set method Amir Main CFD Forum 1 July 7, 2009 10:39
using level set method rubby Main CFD Forum 2 March 7, 2009 03:02
Free surface level set and roe Angela Main CFD Forum 3 October 25, 2002 05:12


All times are GMT -4. The time now is 14:03.