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

How to choose the YPLUS value in two-phase flows?

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

Reply
 
LinkBack Thread Tools Display Modes
Old   February 10, 2007, 20:29
Default How to choose the YPLUS value in two-phase flows?
  #1
Niewlande
Guest
 
Posts: n/a
For two-phase Euler-Euler multiphase model + turbulence model, how to select the reported "yplus" values for meeting the requirement of law-of-the-wall?

I mean, there are two "yplus" values from different phases (say, YPLUS for air & solid). Then, which one should be chosen for the grid adjustment?

Especially, for the MIXTURE and DISPERSED models (k-epsilon multiphase turbulence model), how to make decision for the YPLUS value?

Please give your idea.
  Reply With Quote

Old   December 7, 2015, 11:22
Default
  #2
New Member
 
Jakub
Join Date: Sep 2015
Posts: 20
Rep Power: 2
undziabundzia is on a distinguished road
Anyone knows ? Shall we move that topic, to "meshing problems". I need very much informations, about Yplus wall for water and air, becouse i working on two-phase flow around ship.

Thank You for sharing Your knowledge. You are great !!
undziabundzia is offline   Reply With Quote

Old   December 7, 2015, 16:08
Default
  #3
Senior Member
 
Lucky Tran
Join Date: Apr 2011
Location: Orlando, FL USA
Posts: 1,270
Rep Power: 20
LuckyTran will become famous soon enough
There is no ambiguity in the meaning or definition of y+ for two-phase flows. Just because there may be two different phases in the domain, at a particular location the fluid can only be 1 phase. The exception is the VOF model which allows properties of different phases to be blurred together.

As for post-processing, there really is only one y+ value for the wall adjacent cell (whatever the wall adjacent value is). One y+ will be undefined for the phase that doesn't exist at the wall.

Meshing is no different than single-phase simulation. If you want to predict the grid requirements, then that always requires some knowledge of the expected flow field. Otherwise you can do trial-and-error.
LuckyTran is offline   Reply With Quote

Old   December 7, 2015, 16:43
Default
  #4
New Member
 
Jakub
Join Date: Sep 2015
Posts: 20
Rep Power: 2
undziabundzia is on a distinguished road
Thank You for your reply, Friend.

So If I have Volume of Fluid with Air and Water, that have diffrent y+ from calculator. Which Y+ should I choose ?
undziabundzia 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
alphaEqn.H in twoPhaseEulerFoam cheng1988sjtu OpenFOAM Bugs 15 May 1, 2016 16:12
yplus value in two phase flow P.R.Naren FLUENT 0 September 5, 2006 02:10
Yplus [y+] value for gas solid two phase flow P.R.Naren Main CFD Forum 0 September 5, 2006 02:04
compressible two phase flow in CFX4.4 youngan CFX 0 July 1, 2003 23:32
References fr 2 phase flows in porous media Madhavan Main CFD Forum 2 June 29, 2000 14:01


All times are GMT -4. The time now is 00:43.