[Kostas_K]

Hello everyone,

I am trying to simulate a duct (0.35mx0.35mx0.25m) inside of which a 3d free jet is developed coming out of a sharp-edged rectangular orifice configuration. The flow is incompressible. I want to visualize the velocities values (Ux, Uy, Uz) the vorticities values (Ωx, Ωy, Ωz) and the Reynolds stress (uv, uw) for starters.
I already tried a steady state simulation with the realizable k-epsilon turbulence model. The velocities are good but i can see the vorticity values only at the orifice.
I also tried a transient solution with delayed DES and Spalart Allmaras turbulence model. I have to use as a time step a very small value (2e-05) but the results are very good. However the problem with this one is the residuals are oscillating between the same values for about 2 days now. And i believe it will not converge any time soon or ever.
My mesh is very fine (1.6+ million elements) made up with tetrahedrons and I only used hexahedrons at the boundary layers.
The inlet velocity is 0.13m/s in order to achieve at the orifice, velocities 48~50m/s and so a fully turbulent flow.

My question is if anyone can propose a way to get the results mentioned earlier. Any help is welcome.
I can post if you want the schemes, solver, initial values or BC i already used if it is going to be of some help.

Thank you