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

slip ratio between gas/liquid

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

Reply
 
LinkBack Thread Tools Display Modes
Old   August 17, 2010, 12:11
Default slip ratio between gas/liquid
  #1
New Member
 
Robert Langner
Join Date: Dec 2009
Location: Freiburg, Germany
Posts: 27
Rep Power: 7
Robat is on a distinguished road
Hi foamers!

I have a two phase model in LesInterFoam, where I need to to know the velocity for each phase (of course besides the pressure loss).
My idea was to create an additional volume flux field for one single phase like "phiLiq" via gamma(or alpha) field.
I've made a "elbow-case" like pipe (a gas flow with liquid injection) to test my idea, but it not delivered me a slip ratio.

Does anybody know a good strategy or at least could give me a hint from which value I could get the information to calculate the gas slip ?

bests,
Robert

P.S.: This might be interesting for evaporation models like interDymFoam.
Robat is offline   Reply With Quote

Old   August 17, 2010, 16:54
Default
  #2
Senior Member
 
Holger Marschall
Join Date: Mar 2009
Location: Darmstadt, Germany
Posts: 123
Rep Power: 10
holger_marschall is on a distinguished road
Send a message via Skype™ to holger_marschall
Quote:
Originally Posted by Robat View Post
I have a two phase model in LesInterFoam, where I need to to know the velocity for each phase (of course besides the pressure loss).
Hi Robert,

interFoam is based upon the homogeneous mixture assumption. In consequence you have to live with only a mixture velocity, which in turn demands for a high resolution for both the interfacial morphology (e.g. curvature) and boundary layer.
To evaluate a reasonable local slip velocity (i.e. for under-resolved boundary layers) would need a rewrite of the solver + theoretical work considering phase interaction and interchange...

As a start you might consider the work of M. W๖rner and W. Sabisch, references of whom can be found here: http://bibliothek.fzk.de/zb/berichte/FZKA6889.pdf

In case you have any further questions let me know... I am on another approach considering an interfacial flow solver employing two momentum balances, thus inherently enabling for a interfacial phase slip.

best regards,
__________________
Holger Marschall
web: http://www.holger-marschall.info
mail: holgermarschall@yahoo.de

Last edited by holger_marschall; August 17, 2010 at 16:55. Reason: corrected link
holger_marschall is offline   Reply With Quote

Old   August 18, 2010, 05:41
Default
  #3
New Member
 
Robert Langner
Join Date: Dec 2009
Location: Freiburg, Germany
Posts: 27
Rep Power: 7
Robat is on a distinguished road
Thanks for your quick reply.

I go to check the work of these people.
I'll keep you informed, if I find a good solution.

bests,
Robert
Robat is offline   Reply With Quote

Old   August 18, 2010, 09:05
Default
  #4
Senior Member
 
Holger Marschall
Join Date: Mar 2009
Location: Darmstadt, Germany
Posts: 123
Rep Power: 10
holger_marschall is on a distinguished road
Send a message via Skype™ to holger_marschall
Sure, you are welcome...
Look out for VA-VOF as this method accounts for a phase slip (momentum drift flux term).

best,
__________________
Holger Marschall
web: http://www.holger-marschall.info
mail: holgermarschall@yahoo.de
holger_marschall is offline   Reply With Quote

Reply

Tags
interfoam, slip ratio

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
Slip BC not working properly lfbarcelo OpenFOAM 3 July 15, 2010 09:53
diesel spray combustion equivalence ratio usker CD-adapco 12 March 1, 2008 07:09
Low-Pressure Boundary Slip AlexA FLUENT 1 January 5, 2007 22:30
Free slip and no slip. Yung NUMECA 2 August 16, 2006 09:24
Problem of Turbulent Viscosity Ratio Limited David Yang FLUENT 3 June 3, 2002 06:13


All times are GMT -4. The time now is 20:17.