beginner-hlp pls
 

hi guys i want to set a pressuer of 2 units in movingwall1 and 1 in movingwall .. am getting an error in this could you guys help me with it?:(

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 1.6 |
| \\ / A nd | Web: http://www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
object p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 2 -2 0 0 0 0];

internalField uniform 0;

boundaryField
{
movingWall
{
type fixedValue;
value uniform (1 0 0);
}

movingWall1
{
type fixedValue;
value uniform (2 0 0);
}

fixedWalls
{
type zeroGradient;
}

frontAndBack
{
type empty;
}
}

// ************************************************** *********************** //

A pressure is a scalar, not a vector, so don't use (1 0 0) but simply 1.

However, why do you specify the pressure at a wall, since if you use the no-slip condition, you already specify the velocity, and the pressure should be set to zeroGradient.

Best,

@ alberto
 

Thanks for the reply. Actually I am modifying the cavity problem in the tutorial. I am keeping one face as inlet and the other as outlet. So I named one face of the face as movingwall and an opposite face as movingwall1. I then specified pressure difference as well as velocity difference is this right

You should specify velocity at the inlet, where p is set to zeroGradient, and pressure at the outlet, where velocity is set to zeroGradient. Keep in mind you consider incompressible flows.

@alberto
 

hi.. I understood what you said.. my question is how do i differentiate vectors and scalars when I type them in the editor
hope this is clear

for pressure

movingWall
{
type fixed;
value 0;
}

is this correct?

No it is not correct.

movingWall
{
type fixedValue;
value uniform 0;
}

is the right syntax. This should be clear by all the examples you find in the tutorials.

Best,

Maybe next time you can save your time, and do not reply at all.