I'm gonna be simulating a 3 stage compressor in 5.6. I've worked through the axial stator-rotor tutorial, which has explained the general stuff, but in that case both the stator and the rotor were shrouded. In my problem both are unshrouded, ie I've got a stationary wall just above the tip of the (rotating) compressor blade, and the rotating hub of the compressor just below the tip of the stator blade. If I want to model the relative motion between the blade and the wall, does this imply that I have to model the tip clearance between the blade and the wall? That would obviously lead to very flat elements in that region. I've never CFD'd turbomachinery before so any tips would be really welcome.

Cheers

Louwrens

You really should model the tip gaps. You could attempt to ignore the tip gap and set the appropriate wall BC to rotating, but that's definitely not standard practice in any of the work I've done.