Axial compressor simulation - Max iterations reached

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I’ve been trying the get the hang of SimScale over the past few days by trying to do some fluid dynamics analysis on an axial compressor, I’ve tried 3 different geometries, tonnes of different meshes, and a whole lot of changes to the numerics but I keep getting a ‘max iterations reached’ error, the residual plot has changed as I’ve tried more fixes but currently only my epsilon residual is decreasing. No simulation has passed 3% yet.

Trying to model an axial compressor (Originally I used moving walls but I dropped it since I figured they may have been giving my ‘max iterations’ issues)
Inlet → 40m/s air flow
Outlet → 15bar
Compressible
Air

I feel like there’s one little obvious thing I’m doing wrong but I’ve changed the other relaxation factors as recommended by other tutorials. If anyone could give it a look I would really appreciate it.

Originally I was having errors with my epsilon residual being the only one not decreasing but as in the failed ‘run 1’ now epsilon is the only residual that is decreasing.
Run 1 is a failed run using k-epsilon
Run 2 is a quick run that I’m doing now, the convergence plot shows that It will likely fail

Also just a heads up this isn’t my can file, I got it form the link in the description

Thanks guys

2

Hi @JacksonEmpey!

First of all you are using a tet-dominant mesh but you have to use SnappyHexMesh (Hex-dominant parametric) for problems related to fluid dynamics. Furthermore I want to know if you have another model with which we can create a separate rotating zone because the model you provided us with is not closed and cannot be used properly for the simulation (assuming that you want to have a flow inlet, a rotating domain around your impeller as well as a flow outlet.

I think if you fix the issues for the pre-processing step we are on a good way to achieve good results. If you need any further help please let @Anware and me know!

All the best!

Jousef

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3

Thank you! I’m in the middle of exams now but when I have a minute I’ll give it a try!
Much appreciated!

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