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

Too many VOF sub-timesteps problem

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 10, 2007, 23:02
Default Too many VOF sub-timesteps problem
  #1
wanghong
Guest
 
Posts: n/a
hi,all

i am simulationg a free surface movement using VOF.when the mass flux of mass inlet is defined and time step is 0.002s,my computer tell me: "Updating solution at time level N... Error: Too many (3760548593) VOF sub-timesteps. The velocity field is probably diverging. Please check the solution, and reduce the time-step if necessary. Error Object: ()"

when time-step is 0.2s,error is following: "Updating solution at time level N... Error: Too many (274569734) VOF sub-timesteps. The velocity field is probably diverging. Please check the solution, and reduce the time-step if necessary. Error Object: ()". why? how to do it?

  Reply With Quote

Old   September 11, 2007, 02:38
Default Re: Too many VOF sub-timesteps problem
  #2
garima chaudhary
Guest
 
Posts: n/a
I think u shud try with timp step of .000002 and then gradually reduce n keep no of iteration s per time step at first to 50 and also remove any convergence criteria.and then gardually decrease time step size and then max no of iteratiuon per time step to 20 and then enable convergence criteria
  Reply With Quote

Old   September 11, 2007, 03:48
Default Re: Too many VOF sub-timesteps problem
  #3
wanghong
Guest
 
Posts: n/a
i try it using 0.00002,but my computer rell me:"error:floating point error:invalid number. why? wanghongbjut@yahoo.com.cn
  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
a problem of incompressible two phases(water and gas) with VOF Method zhangweisnoopy Main CFD Forum 9 August 12, 2011 09:25
Two-phase VOF problem scott copland FLUENT 3 March 15, 2007 08:25
Problem with VOF open channel modelling Biswanath Mahato FLUENT 1 September 14, 2006 05:20
A Problem with setting the time step in VOF model Le FLUENT 2 July 20, 2006 23:00
problem with VOF. Marc FLUENT 1 June 5, 2002 09:17


All times are GMT -4. The time now is 17:14.