CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > Siemens

applying boundary condition on rotating wall

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

LinkBack Thread Tools Search this Thread Display Modes
Old   January 16, 2001, 07:33
Default applying boundary condition on rotating wall
Haris Maharana
Posts: n/a
My CFD problem is related to the relative rotation between two parallel no-slip walls (with fluid in-between) at a certain horizontal distance. I will call them as "left wall" and "right wall".

The "left wall" is stationary and the "right wall" is rotating at a certain speed. I am applying the following boundary conditions on these two walls :

1) Left wall : no-slip, omega = 0 ;

2) Right wall : no-slip, omega = some finite value.

Will these boundary conditions take care of the non-rotational effect of the "left wall" and "rotational" effect of the right wall?

If not, can anybody suggest the right way to apply the boundary conditions on these walls?

N.B. : Application of "sliding mesh theory with event module" will to help in this problem.
  Reply With Quote

Old   January 16, 2001, 08:53
Default Re: applying boundary condition on rotating wall
John C. Chien
Posts: n/a
(1). I find it hard to believe that there are non-rotational effect as well as rotational effect. (2). I have not used the code myself. But you shouldn't be worrying about the effect when setting the boundary conditions. (3). If the solution is not responding to the boundary conditions, then it is likely that you are not following the instructions correctly. (4). Well, in your simple problem, you can use either the fixed stationary reference frame (coordinate system) as you just did, or the moving (rotating) reference frame attached to the rotating wall. One is enough. (5). You will have to read your tutorial samples to find out how to set the boundary conditions properly. Each code has its own way of setting the conditions, especially when using the moving reference frame. (6). By the way, what are the non-rotational and rotational effects you are looking for? I have worked in the turbomachinery field for many years, but I have never heard of such effects mentioned before. But anyway, each company always has its own way of defining thing differently. (if you have a rotating wall, the flow field will be rotating everywhere, except fluid particles on the stationary wall. But if you use wall function treatment through turbulence model, you will not see these stationary fluid particles, because then the whole flow field will be all rotating. the fluid layer next to the stationary wall is not computed explicitly when wall function is used.)
  Reply With Quote

Old   January 16, 2001, 13:03
Default Re: applying boundary condition on rotating wall
J. Y. Luo
Posts: n/a
If you are simulating flow between two parallel plates (walls), then the only thing you need to do is specifying the wall boundary conditions as you described. Then through diffusion effect, the velocities will be known to the inside flow.

However, if you have baffles attached to the walls (such as mixing vessel), then you have to use either multiple rotating frames approach or sliding mesh to deal with the problem.
  Reply With Quote


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
rotating wall boundary condition in multiphase sdp FLUENT 0 February 16, 2009 22:12
applying profile data as a boundary condition vadivel CFX 1 June 9, 2007 08:11
Applying Shear Stress at a Boundary Condition Stephen CFX 3 March 27, 2007 19:55
Rotating interpolated boundary condition hani OpenFOAM Running, Solving & CFD 0 July 4, 2006 08:09
A:Inquiry of boundary conditions for rotating wall Gaurav FLUENT 0 June 10, 2005 16:52

All times are GMT -4. The time now is 07:55.