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Roland R January 5, 2012 08:49

Unstable free jet in diffuser

I made a 3D simulation which contains a thin tube (after the inflow), a diffuser and a thick tube (before the outflow ). Value of Re number is about 70000. I tried to complete the simulation with different simulation types (steady state and transient), with different advection schemes but the result was same in every case (it can be seen at the figure).
A képet a Képfeltölté tárolja.

Center of the free jet is not straight after the thin tubes, it is not parallel with the centerline of the tubes.

The geometry is symmetrical, therefore I don’t understand this. Is it a numerical error or a realistic unstable phenomenon?


ghorrocks January 8, 2012 20:44

I cannot access the link. But symmetric geometry resulting in asymmetric flow is quite typical in fluid flow.

khaydar January 30, 2012 17:26

Coanda effect
It may has something to do with the so-called coanda effect.

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