[fpmhadi]

Hi everybody,

I want to specify the boundary conditions in 0 directory files but I’ve got some problems.

I have a fixedWalls boundaryField in my 0/U file and I want to assign a zeroGradient boundary condition for Ux and a fixedValue for Uy, but I do not know how to do it.

This is what I have written already:

fixedWalls
{
U.component(0)
(
type zeroGradient;
)
U.component(1)
(
type fixedValue;
value uniform 0;
)
}

Thanks in advance for your help.
fpmhadi

[gregor]

Hi,
have a look at the slip boundary conditon

http://www.openfoam.com/docs/user/boundaries.php

gregor

[fpmhadi]

Hi,

Thank you very much Gregor.

I was reading that article to fix the problems in my cyclic boundaries!

I tried theses lines, however I am not sure about it:

fixedWalls
{
field U.component(0)
type zeroGradient
field U.component(1)
type fixedValue
value uniform 0;

}

Cheers,
fpmhadi

[gregor]

Originally Posted by fpmhadi

I was reading that article to fix the problems in my cyclic boundaries!

Now i am confused do you want to use cyclic boundaries or a slip condition

In case of slip boundary

fixedWalls
{
type slip;
}

should do.

gregor

[fpmhadi]

No, I was speaking about my two other boundary conditions.

My geometry is a square with two fixedWalls on top and bottom and two cyclic patches on left and right.

Until now I could fix the cyclic problem.

code:

patches
(
cyclic inletoutlet
(
(0 4 7 3)
(2 6 5 1)

)

wall fixedWalls
(
(3 7 6 2)
(0 4 5 1)
)

empty frontAndBack
(
(0 3 2 1)
(4 5 6 7)
)
);

However I really appreciate your help.

fpmhadi