Angle of attack of far field inlet not constant throughout the domain
 

Hello, I am trying to simulate the intake performance in a turbofan at climb conditions, where I have an AoA of 22 degrees. My domain is a box, where one face is set as inlet and the others as openings. At the inlet I specify my angle of attack by decomposing the velocity in Cartesian components, however as seen from the picture attached the direction of the flow comes back to axial direction downstream in the domain.

I have tried to rotate my mesh and kept constant the axial velocity, and also set more faces as inlets but nothing. Any suggestions??

You need your top and bottom domain faces as inlet as well.

The issue was that the inlet domain was initialized with axial velocity. Now the problem I am having is with convergence. The strategy I have been following for the case with no angle of attack has been as follows, with no problems:

Turbulence scheme: 1st order
Advection scheme: Upwind
Auto Timescale factor 1 for 200 iterations

Turbulence scheme: 2nd order
Advection scheme: 2nd order
Auto Timescale factor 1 for 200 iterations
Auto Timescale factor 2 for 200 iterations
Auto Timescale factor 5 for 200 iterations
Auto Timescale factor 10 for 200 iterations

However now, with an angle of attack, at Auto Timescale factor 1 it crashes, so I am trying with local time scale instead:

Turbulence scheme: 1st order
Advection scheme: Upwind
Local Timescale factor 2 for 200 iterations

Turbulence scheme: 2nd order
Advection scheme: 2nd order
Local Timescale factor 2 for 200 iterations
Auto Timescale factor 1 for 200 iterations
Auto Timescale factor 2 for 200 iterations
Auto Timescale factor 5 for 200 iterations
Auto Timescale factor 10 for 200 iterations

Does it make sense to you? Any other idea for the convergence strategy?

Thanks in advance.

Hard coding a time step is not much good in a steady state simulation. A much better way of doing it is to start with a small time step and adjust it as you go using "Edit run in progress". If the simulation is monotonically converging then increase the time step, if it is starting to diverge then decrease the time step.

Also read this FAQ: https://www.cfd-online.com/Wiki/Ansy...gence_criteria (including the bit about local time scale factor)

It actually did converge with this strategy so problem solved. Thanks a lot for your help!