[chubb87]

Hello,

I am simulating a journal bearing and the velocity at the outlet boundary looks strange:
At the edge of the outlet (see picture) at the moving wall there is a sudden jump in the velocity from 8 m/s to 60 m/s, which occurs only in one cell layer next to the moving wall patch (which is moving with 8 m/s to the left) and seems to be unphysical.

I suspect the reason might be the boundary conditions, which are as follows:
At outlet:
p - fixedValue
U - zeroGradient

at moving wall:
p - zeroGradient
U - movingWallVelocity


And at the symmetry of course symmetry condition.

This jump in velocity is most pronounced at the wall meeting the symmetry patch and the outlet (where backflow occurs). Unfortunately I do not know which boundary conditions might be a better choice for the outlet. Can you give me advice?
Thanks in advance.