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-   -   Slip & No Slip Conditions (http://www.cfd-online.com/Forums/openfoam/84549-slip-no-slip-conditions.html)

kurne February 2, 2011 06:15

Slip & No Slip Conditions
 
Dear All
Will anybody please tell me how to give the Slip and Noslip conditions at the wall.I am bit confused, whether slip means zeroGradient and Noslip means fixedGradient.

madad2005 February 2, 2011 06:25

To implement no-slip, use:

type fixedValue;
value (0,0,0);

To implement slip, use:

type slip;

kurne February 2, 2011 06:39

Dear madad2005
Thanks A lot for help.Will you please correct me
For No Slip conditions
1) For velocity
type fixedValue;
value uniform 0;
2) For pressure
type fixedValue;
value uniform 0;
For Slip Conditions
1) For velocity
type slip;

2) For pressure
type slip;

Thanks In Advance

madad2005 February 2, 2011 06:57

Quote:

Originally Posted by kurne (Post 293258)
Dear madad2005
Thanks A lot for help.Will you please correct me
For

No Slip conditions
1) For velocity
type fixedValue;
value uniform (0,0,0);

2) For pressure
type zeroGradient;

For Slip Conditions
1) For velocity
type slip;

2) For pressure
type zeroGradient;

Thanks In Advance

See above. The BC requirement for pressure at the wall is normally zeroGradient. For velocity with a slip wall, there are two different conditions to be met normal to the wall and parallel to the wall, which I believe the slip boundary condition handles.

kurne February 2, 2011 07:05

Dear mada2005
Thank you very much for guiding me.
Thanks Once Again.

Prash November 20, 2013 12:58

Quote:

Originally Posted by madad2005 (Post 293260)
See above. The BC requirement for pressure at the wall is normally zeroGradient. For velocity with a slip wall, there are two different conditions to be met normal to the wall and parallel to the wall, which I believe the slip boundary condition handles.

Hi all,
sorry to revive such an old post.
1. If I use full-slip for velocity, is there a need to specify pressure ? I guess it should calculate using the velocity at the wall ?

2. What if I use pressure bc as "slip" as well with Velocity bc as "slip" . It should be same as pressure bc "zeroGradient" ? I do not get same answers if I do this.


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