CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   OpenFOAM (https://www.cfd-online.com/Forums/openfoam/)
-   -   Boundary condition at infinity (https://www.cfd-online.com/Forums/openfoam/78324-boundary-condition-infinity.html)

Janez Turk July 18, 2010 20:08

Boundary condition at infinity
 
Hello,

Is there some way to set BC (of p and U) to some value very far from the object?

To illustrate:
In this picture there are BC on cricle and very far away from it. There is no additional wall or someting.
http://www.stkate.edu/physics/Flight...are%5B1%5D.gif

thankyou
Janez

chrisb July 19, 2010 02:29

Quote:

Originally Posted by Janez Turk (Post 267925)
Hello,

Is there some way to set BC (of p and U) to some value very far from the object?

To illustrate:
In this picture there are BC on cricle and very far away from it. There is no additional wall or someting.
http://www.stkate.edu/physics/Flight...are%5B1%5D.gif

thankyou
Janez

Hi Janez,

I would suggest that you do some reading! There is no real concept within openFOAM of an infinite boundary condition. Rather you have to create a mesh such that the boundary is far (enough) away from your zone of interest to approximate infinite boundary conditions. At the 'freestream' boundaries you may impose a set of infinite conditions. Testing whether or not this boundary is far enough away to not influence results is important to validating your work.

For an example see $FOAM_TUTORIALS/incompressible/simpleFoam/airFoil2D

Cheers
CB

P.S. Many CFD textbooks and papers will cover this topic.


All times are GMT -4. The time now is 01:28.