Flow on the wall and boundary conditions

Waggy · February 18, 2018, 08:31

Hi,
I'm new in OpenFOAM and I'm trying to simulate injection of helium into surrounding air (N2/O2/H2O = 0.77/0.225/0.005) with surface (wall) which is located at distance 3 cm from the helium's outlet and perpendicular to the helium's flow.

Firstly, I simulated helium ejecting into air without the wall. In order to do that I used reactingFoam without combustion and chemical reactions.

But I don't know what kind of boundary condition should I use then I want to add the wall. I want the helium's flow to flow along the wall, so I should make normal component of the flow's speed equal zero.

How to do that?

piu58 · February 18, 2018, 13:42

If you want to have a real wall, then you have to use the no slip b.c.
If you want to limit your region you have to use symmetric plane or slip b.c.

Waggy · February 19, 2018, 01:45

Thanks for that

February 18, 2018, 08:31	Flow on the wall and boundary conditions	#1
Waggy New Member Sergey Join Date: Feb 2018 Posts: 8 Rep Power: 8	Hi, I'm new in OpenFOAM and I'm trying to simulate injection of helium into surrounding air (N2/O2/H2O = 0.77/0.225/0.005) with surface (wall) which is located at distance 3 cm from the helium's outlet and perpendicular to the helium's flow. Firstly, I simulated helium ejecting into air without the wall. In order to do that I used reactingFoam without combustion and chemical reactions. But I don't know what kind of boundary condition should I use then I want to add the wall. I want the helium's flow to flow along the wall, so I should make normal component of the flow's speed equal zero. How to do that?

February 18, 2018, 13:42		#2
piu58 Senior Member Uwe Pilz Join Date: Feb 2017 Location: Leipzig, Germany Posts: 744 Rep Power: 15	If you want to have a real wall, then you have to use the no slip b.c. If you want to limit your region you have to use symmetric plane or slip b.c. __________________ Uwe Pilz -- Die der Hauptbewegung überlagerte Schwankungsbewegung ist in ihren Einzelheiten so hoffnungslos kompliziert, daß ihre theoretische Berechnung aussichtslos erscheint. (Hermann Schlichting, 1950)

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February 19, 2018, 01:45		#3
Waggy New Member Sergey Join Date: Feb 2018 Posts: 8 Rep Power: 8	Thanks for that