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-   -   ouflow boundary problem (http://www.cfd-online.com/Forums/openfoam-solving/124628-ouflow-boundary-problem.html)

izna October 9, 2013 11:49

ouflow boundary problem
 
Hi..
I am simulating flow around some shapes, in 2D.
I used simpleFoam and PCG solver with K-epsilon . My aim is to put my 3 boundaries as Outflow.. and my 1 bounday as inlet..

Hence i use the Zero gradient bC.. But alas i obtain the following results..

Can anyone please advice me on which BC to use and how please..

ARTem October 14, 2013 08:18

Hello, izna O'connor.
Is your flow supersonic? If not, you should specify pressure or velocity at outlet (i.e. not zeroGrad for all variables).
Are you sure that substance strictly flows out through this 3 boundaries (by physics, not by mathematics)? If so, you can cast restriction by using following BC "type inletOutlet; inletValue uniform (0 0 0); value uniform (0 0 0);".

izna October 14, 2013 08:30

hello ARtem..

can you please check those posts? http://www.cfd-online.com/Forums/ope...tml#post456727

I cannt run it with simpleFooam and its not supersonic..

shuoxue November 2, 2013 07:00

Quote:

Originally Posted by izna (Post 455976)
Hi..
I am simulating flow around some shapes, in 2D.
I used simpleFoam and PCG solver with K-epsilon . My aim is to put my 3 boundaries as Outflow.. and my 1 bounday as inlet..

Hence i use the Zero gradient bC.. But alas i obtain the following results..

Can anyone please advice me on which BC to use and how please..

Hi, izna!

Have you found out the way to simulate outflow BC with openfoam?

I'm solving a flow around cylinder case with interFoam. I have tried freestream and freestreamPressure BC in U and p files. However, the drag coefficient doesn't match the values announced in papers.


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