Farfield BCs for wing in free flow

jammy4536 · February 9, 2021, 06:41

I have a simulation of an M6 wing, that is having trouble with the farfield boundary. The farfield is hemispherical, with a symmetry plane.

At the inlet side of the hemisphere, the pressure is significantly lower than it should, but velocity is more or less what it should be. However after the lower pressure, the velocity surrounding the wing is lower than it should be. Currently the BCs are freestreamVelocity (Vinf = 39.93) and freestreamPressure (Pinf = 101353).

In various 2D sims I've done around aerofoils, these BCs have worked perfectly well, so I'm really confused why they aren't giving a good BC for this 3D sim. My best guess is something about it interacting with the symmetry plane, but that still doesn't help me fix the issue.

Any help is much appreciated!

jammy4536 · February 11, 2021, 11:02

So this was simply a very trivial mistake...
I put the vertical velocity component in the y-direction, not the z-direction. This made it seem like it was coming out of the symmetry plane, and caused the anomaly. Works perfectly fine when in the correct axis.

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February 11, 2021, 11:02		#2
jammy4536 New Member Jamie MacLeod Join Date: May 2020 Posts: 9 Rep Power: 6	So this was simply a very trivial mistake... I put the vertical velocity component in the y-direction, not the z-direction. This made it seem like it was coming out of the symmetry plane, and caused the anomaly. Works perfectly fine when in the correct axis.