# Square cylinder non-symmetric results?

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September 27, 2022, 16:02
Square cylinder non-symmetric results?
#1
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Hi all,

I am using buoyantBoussinesqPimpleFoam to solve a simple case with a square cylinder but although the velocity contours seem to be OK (Karman vortex street forming past the square cylinder, the pressure contours neither look symmetrical nor right.

I am attaching the important bits of the initial conditions set for U and p_rgh:

Code:
```dimensions [0 1 -1 0 0 0 0];

internalField uniform (19.68 0. 0.);

boundaryField
{
outlet
{
type inletOutlet;
inletValue   uniform (19.68 0. 0.);
value        uniform (19.68 0. 0.);
}

upperLower
{
type symmetry;
}

inlet
{
type fixedValue;
value    uniform (19.68 0. 0.);
}

symPlane
{
type symmetry;
}

cylinder
{
type fixedValue;
value    uniform (0. 0. 0.);
}
}```

Code:
```dimensions [0 2 -2 0 0 0 0];

internalField uniform 0.;

boundaryField
{
outlet
{
type            fixedValue;
value           uniform 0.;
}

upperLower
{
type symmetry;
}

inlet
{
}

symPlane
{
type symmetry;
}

cylinder
{
}

}```
I'm also setting the kinematic viscosity to nu = 0.000656 m^2/s and since the square cylinder's side is 0.01 m long and u_inf = 19.68 m/s, Re = 300.

I tried different mesh densities (some of them quite fine) and all of them seem to behave in the same way, there's a spot over the square cylinder or below it where the pressure contours behave in a strange manner.

What am I doing wrong? Are the Boundary Conditions OK? Could it be the mesh? I'm a bit lost.

(I'm using this solver as I want to do a slip study, but in this case there was no slip and yet the results look this strange).

Thank you very much in advance.
Attached Images
 U.png (48.4 KB, 5 views) P.png (92.1 KB, 6 views)

 Tags buoyantboussinesq, divergence, mesh, pressure, symmetry

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