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

I need to fix total volume fraction

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   January 17, 2007, 08:32
Default I need to fix total volume fraction
  #1
Yasser
Guest
 
Posts: n/a
hello i am using eulerian two phase model to simulate the flow in mixing tank. after post processing, i find the solid volume fraction become lower than its patched value ....

I read that another one used UDF to fix the total volume fraction to a certain value and he gave this link in the references

http//www.fluentusers.com/udf_archieve/udf_examples/UDF52.htm

but i don't have access to this site can anyone help me? thank you
  Reply With Quote

Old   January 17, 2007, 13:12
Default Re: I need to fix total volume fraction
  #2
Suijth
Guest
 
Posts: n/a
what is your simulation?

If you just want to keep the initial values of the vol fraction, you can turn off the volume fraction equation from solving it, in the solution controls panel..

-Sujith S Nair
  Reply With Quote

Old   January 17, 2007, 13:24
Default Re: I need to fix total volume fraction
  #3
Yasser
Guest
 
Posts: n/a
i am modelling two phase flow (solid-liquid) in mixing tank and thx for your suggestion

i don't want to keep the initial values ... i am studying solids concentration. just i need the total volume fraction in the tank be the same as initially patched.

thx for reply
  Reply With Quote

Old   January 17, 2007, 17:19
Default Re: I need to fix total volume fraction
  #4
Sujith
Guest
 
Posts: n/a
After patching your initial value of the patched variable will be over written. if u want to keep this for rest of simulation , you can switch off vof eqn.
  Reply With Quote

Old   January 17, 2007, 17:47
Default Re: I need to fix total volume fraction
  #5
Yasser
Guest
 
Posts: n/a
Thanks very much
  Reply With Quote

Old   January 18, 2007, 02:25
Default Re: I need to fix total volume fraction
  #6
Yasser
Guest
 
Posts: n/a
hello now i turned the equation off, but the volume fraction didn't change from cell to another

i need the volume fraction of solids to change from cell to another but i need the average volume concentration overall the tank to remain constant (which is not happened when turning the vof eq. on).

thx

Yasser

  Reply With Quote

Old   August 1, 2011, 15:14
Default Urgent!!
  #7
New Member
 
Olusogo fire
Join Date: Jun 2011
Posts: 9
Rep Power: 6
phire is on a distinguished road
pls yasser. I am working on the scour under pipeline. I am having the same problem you had. Where you able to find solution to it. I will really appreciate your response cos I have to submit my Thesis by august 9. thank you very much
phire is offline   Reply With Quote

Old   August 1, 2011, 15:15
Default
  #8
New Member
 
Olusogo fire
Join Date: Jun 2011
Posts: 9
Rep Power: 6
phire is on a distinguished road
Quote:
Originally Posted by Yasser
;138273
hello now i turned the equation off, but the volume fraction didn't change from cell to another

i need the volume fraction of solids to change from cell to another but i need the average volume concentration overall the tank to remain constant (which is not happened when turning the vof eq. on).

thx

Yasser
pls yasser. I am working on the scour under pipeline. I am having the same problem you had about the volume fraction reducing. Were you able to find solution to it. I will really appreciate your response cos I have to submit my Thesis by august 9 I can get result due to the wrong volume fraction result. thank you very much
phire is offline   Reply With Quote

Old   August 3, 2011, 08:10
Default
  #9
New Member
 
zino
Join Date: Mar 2010
Posts: 23
Rep Power: 7
zino is on a distinguished road
I think you need mass conservation. there are options in multiphase. I have used eulerian approach. that approach provide mass conservation option
zino is offline   Reply With Quote

Old   August 3, 2011, 13:37
Default
  #10
New Member
 
Olusogo fire
Join Date: Jun 2011
Posts: 9
Rep Power: 6
phire is on a distinguished road
@zino Pls how do I set mass conservation because I am using eulerian granular phase model in which sand is taken as the granular phase while water is the continuum
phire is offline   Reply With Quote

Reply

Thread Tools
Display Modes

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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Volume fraction of dispersed phase to determine DPM, VOF, Mixture model Mohsin FLUENT 3 January 30, 2015 13:47
multiphase... solid volume fraction anomaly Tim CFX 4 February 14, 2012 05:01
Multiple floating objects CKH OpenFOAM 10 September 21, 2011 23:13
alphaEqn.H in twoPhaseEulerFoam cheng1988sjtu OpenFOAM Bugs 14 September 18, 2011 13:46
Volume Fraction cheong FLUENT 1 November 28, 2001 05:06


All times are GMT -4. The time now is 22:32.