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

gas hold up/gas volume fraction

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

Reply
 
LinkBack Thread Tools Display Modes
Old   March 27, 2009, 08:52
Default gas hold up/gas volume fraction
  #1
New Member
 
chaker rym
Join Date: Mar 2009
Posts: 14
Rep Power: 8
CHAKER is on a distinguished road
can any one please tell me about the difference between gas hold up and gas volume fraction.
regards
CHAKER is offline   Reply With Quote

Old   May 7, 2009, 13:58
Default
  #2
New Member
 
Sandeep
Join Date: Mar 2009
Location: Blacksburg, US
Posts: 3
Rep Power: 8
sanbhat is on a distinguished road
Typically hold up is termed for liquids.
May be gas holdup = 1-liquid holdup.
Anyways, input GVF= Q_g/(Q_g + Q_l). It is based on the flow rates. It gives an idea on the area fraction covered by the gas, liquid if both are moving with same velocity.

But, if there is slip, the gas tends to move with higher speed than the liquid. During this time, the in-situ volume fractions for both phases will be very different. because, gas occupies less area than the liquid due to mass conservation principle.Typically, liquid holdup is calculated using emperical correlations.

Regards,
sanbhat
sanbhat is offline   Reply With Quote

Old   May 7, 2009, 18:02
Default
  #3
New Member
 
chaker rym
Join Date: Mar 2009
Posts: 14
Rep Power: 8
CHAKER is on a distinguished road
Thanks...
regards
CHAKER
CHAKER 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
BlockMesh FOAM warning gaottino OpenFOAM Native Meshers: blockMesh 7 July 19, 2010 14:11
On the damBreak4phaseFine cases paean OpenFOAM Running, Solving & CFD 0 November 14, 2008 22:14
CFX Solver Memory Error mike CFX 1 March 19, 2008 08:22
fluent add additional zones for the mesh file SSL FLUENT 2 January 26, 2008 12:55
Axisymmetrical mesh Rasmus Gjesing (Gjesing) OpenFOAM Native Meshers: blockMesh 10 April 2, 2007 14:00


All times are GMT -4. The time now is 06:40.