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-   -   Boundary Condition for Far Field? (http://www.cfd-online.com/Forums/openfoam-pre-processing/83185-boundary-condition-far-field.html)

Aneirin December 18, 2010 14:45

Boundary Condition for Far Field?
 
Hello,

I am trying to model the (subsonic compressible) flow over a moving object (like an airfoil). In Fluent, one can specify FarField boundary conditions, but I can not find something similar in OpenFOAM, at first glance (I looked through the source code for Derived Types, as mentioned in the Manual).

Has anyone succesfully completed such a simulation - and which boundary conditions did you use to do so? Details with regard to such simulations seem very scarce, I looked in numerous places.

Help would certainly be appreciated.

fletc900 January 20, 2011 17:49

Hi there,

There is the "freestream" patch type. Take a look at the airfoil2D example under the simpleFoam directory for the tutorials that uses a c-mesh. In the 0/ directory, for the U file (and other variable files) , you should have something like:

boundaryField
{
inlet
{
type freestream;
freestreamValue uniform (43.71427 3.05657365 0); // angle of attack = 4 deg
}

outlet
{
type freestream;
freestreamValue uniform (43.71427 3.05657365 0);
}

wall
{
type fixedValue;
value uniform (0 0 0);
}

frontAndBack
{
type empty;
}
}

Cheers


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