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

free surface inside a stirred tank

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 10, 2002, 03:51
Default free surface inside a stirred tank
  #1
mystic_cfd
Guest
 
Posts: n/a
I am modelling flow in a stirred tank with a free top surface. Presently I solve the case using geo-reconstruct, but this consumes huge amounts of time - my feeling is that its the free surface algorithm. 2 questions:

1) which of the other VOF can be recommended for the free surface if the actual shape and location is not mission critical.

2) is there a way to monitor how much time the solver spends on solving the geo-reconstruction VOF?

thanks
  Reply With Quote

Old   December 10, 2002, 04:10
Default Re: free surface inside a stirred tank
  #2
MissNancy
Guest
 
Posts: n/a
1) geo-reconstruction VOF 2) what do you mean by that, do you mean how much extra time it takes to calculate the VOF part as compared to not considering the free surface? Why do you need this ??

Nancy
  Reply With Quote

Old   December 10, 2002, 05:50
Default Re: free surface inside a stirred tank
  #3
mystic_cfd
Guest
 
Posts: n/a
1) when using Fluent 6, the recommended (by manual) option for solving VOF problems, is the geo-reconstruct method, described as a piecewise linear reconstruction of the VOF interface.

2) some time in the iteration loop will be spent doing this interface reconstruction - in my case I have a feeling it takes "forever". i would like to know if anyone has ideas on how to measure this.
  Reply With Quote

Old   December 10, 2002, 06:22
Default Re: free surface inside a stirred tank
  #4
MissNancy
Guest
 
Posts: n/a
At the end of the day, you will conclude that "The VOF simulation in Fluent is total sh**t*"

Sorry for my language

Nancy
  Reply With Quote

Old   December 11, 2002, 04:07
Default Re: free surface inside a stirred tank
  #5
boris
Guest
 
Posts: n/a
If the free-surface is not so critical in your problem, you maybe can try implicit Eulerian with second order discritization scheme. It is much faster. But, the interface between two phases obtained from the results is not sharp. That is the limitation. VOF of Fluent is really frustrating. I totally agreed with Miss Nancy. So, be patient.
  Reply With Quote

Old   December 11, 2002, 10:27
Default Re: free surface inside a stirred tank
  #6
stan tonks
Guest
 
Posts: n/a
If the surface is not mission-critcal why not model it as a no-slip boundary
  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
Thermocapillary free surface flow zakifoam OpenFOAM Running, Solving & CFD 10 December 12, 2016 12:44
Submarine Free Surface samwh CFX 7 August 30, 2009 08:14
Floating ball on free surface validations Bak_Flow Main CFD Forum 0 November 10, 2008 16:57
free surface display carno Siemens 4 October 7, 2005 02:03
Modeling Free Surface Flows Elliot Schwartz Main CFD Forum 5 August 25, 1998 22:03


All times are GMT -4. The time now is 08:33.