CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

No Slip Boundary conditions

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 27, 2008, 11:31
Default Hi People, I am trying to j
  #1
New Member
 
Lawrence
Join Date: Mar 2009
Posts: 8
Rep Power: 17
lawrencelkl is on a distinguished road
Hi People,

I am trying to justify my choice of no slip boundary conditions for a wall shear stress study:

(1) it simply means the fluid is not moving at the wall surface

(2) slip can be used if the shear components are specified, but will not be appropriate in this case since i am interested to find the wall shear stress

(3) the no slip boundary condition should account for highest wall shear stress compared to cases with slip, thus conservative results

Please correct me ( especially (3)) if i am wrong. any comments and helps will be very much appreciated.
cheers

Lawrence
lawrencelkl is offline   Reply With Quote

Old   May 27, 2008, 11:44
Default All 3 of your statements seem
  #2
New Member
 
Edward Reed
Join Date: Mar 2009
Posts: 12
Rep Power: 17
edreed is on a distinguished road
All 3 of your statements seem accurate to me.
edreed is offline   Reply With Quote

Old   May 27, 2008, 11:51
Default By turning on the no slip boun
  #3
Senior Member
 
Anonymous
Join Date: Mar 2009
Posts: 110
Rep Power: 17
madad2005 is on a distinguished road
By turning on the no slip boundary condition you are essentially saying that the surface has roughness and so you will get a proper boundary layer profile. Without it, you won't get any surface shear stresses or any viscous drag.

(1) A boundary layer has zero velocity at the wall and tends to 0.99*Ufreestream at its edge. So, yes.

(2) I suppose you could, but why since it is a bit of a fudge? You need no-slip if you want to predict what these shear stresses are.

(3) Not sure what you mean here.

I find it strange you have to justify applying the no-slip condition, especially for a shear stress study. I thought it'd be more the case if it was the other way around.
madad2005 is offline   Reply With Quote

Old   May 27, 2008, 12:00
Default Hi Edward and Adriano, Than
  #4
New Member
 
Lawrence
Join Date: Mar 2009
Posts: 8
Rep Power: 17
lawrencelkl is on a distinguished road
Hi Edward and Adriano,

Thanks for your replies and help. Seems like no-slip Boundary condition is the right way to go for this case.

I am asking for help here because someone questioned my choice of such condition but now i will be much more confident when explaining the choice.

Cheers

Lawrence
lawrencelkl is offline   Reply With Quote

Old   June 19, 2018, 02:33
Default
  #5
New Member
 
sthish
Join Date: May 2012
Posts: 11
Rep Power: 13
sathishkrazy is on a distinguished road
Hello madad,

According to you , if we are specifying no Sliip it accounts for Surface Roughness, so You mean to say irrespective of material pressure drop will be same when we specify no slip ?
sathishkrazy is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Boundary details, free slip or no slip? Tiago CFX 5 August 20, 2013 23:54
free slip boundary conditions Yang Main CFD Forum 8 May 22, 2011 23:14
Slip boundary conditions NS-fan Main CFD Forum 6 October 21, 2010 10:00
Continumm flow with slip boundary conditions !! Sohag CFX 2 June 14, 2007 10:56
Navier-Stokes with slip Boundary conditions Leo González Main CFD Forum 5 December 23, 2000 17:16


All times are GMT -4. The time now is 07:13.