CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   OpenFOAM (http://www.cfd-online.com/Forums/openfoam/)
-   -   viscoelasticFluidFoam (http://www.cfd-online.com/Forums/openfoam/93432-viscoelasticfluidfoam.html)

viscoelasticFluidFoam

Hi Foamer's
i have some question about viscoelasticFluidFoam solver
1-how i can set velocity for wall in this solver(similar to cavity solver) u=U
2-how i can set BC's for outlet like Pressure outlet in Fluent ,i cant use the zero Gradient bc's for the outlet.

Thanks Lot Engineer's

 nimasam October 15, 2011 15:33

Hi Foamer's
i have some question about viscoelasticFluidFoam solver
1-how i can set velocity for wall in this solver(similar to cavity solver) u=U
as you said similar to cavity case
Code:

```type      fixedValue; value    uniform (1 0 0);```
2-how i can set BC's for outlet like Pressure outlet in Fluent ,i cant use the zero Gradient bc's for the outlet.
usually outlet pressure is known and its ambient pressure, so it is fixed
Code:

```type      fixedValue; value    uniform 0;```

Thanks Lot Engineer's

Thanks Dear Nima
If I want set the 2 BC's For 1 wall(for example in 2D , Uper Wall) such as:
1) type fixedValue;
value uniform (1 0 0);
and ∂V/∂y=0
How I can??
I want solve the B.Layer Theory in Viscoelastic Fluid's

Thanks

 ata October 16, 2011 06:48

Hi Usef
What kind of BC is this?

Pressure bc's

Hi
My Geometry is 4*2 Square
Uper Wall: velocity u=U
Bottom Wall: Fixed Wall
Left Wall: Velocity Inlet
Right Wall:Pressure Outlet

In OpenFOAM BC'S
Pressure BC's:

HTML Code:

```dimensions      [0 2 -2 0 0 0 0]; internalField  uniform 0; boundaryField {     Inlet       {           type            zeroGradient;     }     Up         {         type          zeroGradient;       }         Outlet     {         type            fixedValue;         Value          uniform 0;         }         Bottom     {         type            zeroGradient;     }         frontAndBack     {         type            empty;     } }```
However
The BC'S for pressure is Right??
but in solving time get ERROR that Below:
Quote:
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *// Create time Create mesh for time = 0 Reading field p keyword inlet is undefined in dictionary "/home/joseph/OpenFOAM/joseph-1.5-dev/run/PTT-Linear/0/p::boundaryField" file: /home/joseph/OpenFOAM/joseph-1.5-dev/run/PTT-Linear/0/p::boundaryField from line 33 to line 54. From function dictionary::subDict(const word& keyword) const in file db/dictionary/dictionary.C at line 271. FOAM exiting
Where is the problem??
Thanks Lot Foamer's

 nimasam October 16, 2011 17:12

dear usef
be more careful before you send each ur problem and read the error line! it will save ur time and other user times ;)
its obvious ur boundary inlet is undefined u use Inlet instead of inlet! (attention to I)

Quote:
 Originally Posted by nimasam (Post 328126) dear usef be more careful before you send each ur problem and read the error line! it will save ur time and other user times ;) its obvious ur boundary inlet is undefined u use Inlet instead of inlet! (attention to I)
Hi Nima
i Defined in gambit Inlet(I)
and over and over i simulated another solver with this
the problem is another place in code.
thank you

 ata October 17, 2011 05:46

Hi dear Usef
According to the error you have got it seems that Nima is right.
I think you do not need two BC for velocity on one boundary. I think you can set the normal gradient of stress equal to zero on that boundary.
Good luck

Ata

Hi Dear's
My BS'c In gambit:
Inlet
Outlet
Up
Bottom

i think problem is another...