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

partial slip to moving wall

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 29, 2017, 08:17
Default partial slip to moving wall
  #1
Member
 
Ashok
Join Date: Feb 2017
Posts: 31
Rep Power: 3
ashokmoravaneni is on a distinguished road
Hello everyone,

can any one tell me how to apply partial slip BC to a wall moving with velocity(say for ex.-0.6679 vertically down). I have defined BC of moving wall like below in U field.
in U field:
movingWall
{
type partialSlip;
value uniform (0 -0.6679 0);
valueFraction uniform 0.5;
}
in P field:
movingWall
{
type zeroGradient;

}

If I define velocity as mentioned in U field above, the wall doesnt take any velocity. Only if fixed value is assigned like this, wall is moving.
movingWall
{
type fixedValue;
value uniform (0 -0.6679 0);
}

Any kind of help is appreciated. Thanks in advance.
ashokmoravaneni is offline   Reply With Quote

Old   August 30, 2017, 17:26
Default
  #2
Member
 
Yousef
Join Date: Feb 2015
Posts: 35
Rep Power: 5
ykanani is on a distinguished road
For many boundary conditions, the "value" entry specified in the boundary condition is just an initial value and I believe this is the case for the partial slip as well.
This is not the case for the fixedValue where OpenFOAM imposes the value according the the "value" entry in the boundary condition throughout the simulation.

I think this explains your observation. I don't know how you can apply partial slip on a moving wall though.

Regards,
ykanani is offline   Reply With Quote

Old   August 30, 2017, 17:57
Default
  #3
Member
 
Ashok
Join Date: Feb 2017
Posts: 31
Rep Power: 3
ashokmoravaneni is on a distinguished road
Quote:
Originally Posted by ykanani View Post
For many boundary conditions, the "value" entry specified in the boundary condition is just an initial value and I believe this is the case for the partial slip as well.
This is not the case for the fixedValue where OpenFOAM imposes the value according the the "value" entry in the boundary condition throughout the simulation.

I think this explains your observation. I don't know how you can apply partial slip on a moving wall though.

Regards,
Thank you for your Respose. I still couldn't find out how to implement partial slip to a moving wall. One can apply partial slip to a fixed wall in which fluid flows.

But in my case it is reverse. Fluid is filled in a cylindrical tube closed an bottom and side walls are moved with some velocity. So I wanted to give velocity and partial slip at the same time to my wall.
ashokmoravaneni is offline   Reply With Quote

Old   March 3, 2018, 13:55
Default
  #4
Member
 
vishal
Join Date: Mar 2013
Posts: 73
Rep Power: 7
vishal_s is on a distinguished road
Hello Ashok,

I am also trying the same thing. Did you figure out how to implement it?
vishal_s is offline   Reply With Quote

Old   March 8, 2018, 11:37
Default
  #5
Senior Member
 
Saideep
Join Date: Apr 2015
Location: INDIA
Posts: 191
Rep Power: 5
Saideep is on a distinguished road
May be I am completely wrong but I am trying to understand how this can be done.

Partial Slip:

means the wall is stationary but the wall cell faces can have a non-zero velocity.
Impact: reduces/ relaxes large magnitudes of viscous forces/ stresses on the boundary cells.

Is the analogy not same considering a moving wall with a no-slip boundary condition? That is (please correct me if wrong), there are only two possibilities but not sure what happens. Either the parabolic flow profile is violated, else as above the viscous forces reduce in magnitude.

I somehow get a feeling that movingWall with slip can be dealt by just using slip/ partial slip.
Saideep 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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Free slip moving wall BC Claudio OpenFOAM Running, Solving & CFD 26 September 3, 2018 05:17
Fluent3DMeshToFoam simvun OpenFOAM Other Meshers: ICEM, Star, Ansys, Pointwise, GridPro, Ansa, ... 49 July 2, 2018 23:50
Natural convection in a closed domain STILL NEEDING help! Yr0gErG FLUENT 3 June 12, 2013 03:12
Errors running allwmake in OpenFOAM141dev with WM_COMPILE_OPTION%3ddebug unoder OpenFOAM Installation 11 January 30, 2008 21:30
Multicomponent fluid Andrea CFX 2 October 11, 2004 06:12


All times are GMT -4. The time now is 22:13.