[NereusC]

Problem with running a simulation in ANSYS Fluent 13.
Solution is converging perfectly but strange things happen in the velocity profile in the wake region.
Strange thing: At the outlet as you may see by looking at the figure below there are some kind of velocity instabilities which to me look very unphysical. What is expected is at the outer boundary the velocity should be again freestream velocity.
Suggestions are more than welcome!

Boundary conditions: Inlet velocity, Pressure (gage) at the outlet is zero, everything else is wall.
Result is from Spalart-Allmaras.

EDIT - The run is unsteady and is running for six revolutions of the blades (simulation of a vertical wind turbine).