InterFoam hydro turbine
 

Hi guys, I've been trying to simulate a multiphase hydraulic turbine for months with interFoam. I need someone who has experience for my thesis. My boundary conditions are as follows:
alpha.water
inlet fixed value uniform 1
outlet inletOutlet inletValue uniform 0 value uniform 0
wall zeroGradient
AMI1 and AMI2 cyclicAMI
symmetry on the back and front ( I 'm simulate 2D case for now)

k,omega are turbulente inlet and wall functions with an arbitrary value (the simulation does not go well in the laminar conditions)

for U i have:
inlet fixedValue (10.74 0 0)
outlet pressureInletOutletVelocity
wall no slip

fo p_rgh:
inlet fixedFluxPressure
outlet fixedValue uniform 0
wall fixedFluxPressure

For the preliminary study I use MRF with 1000 rpm.
The turbine starts full of air and the water begins to enter, already here I have the first problems because the air reaches very high speeds and crashes the simulation. I tried initializing with turbine full of water but nothing done. I tried to initialize with 0 rpm but still the timestep is really low (1e-7 on average).I've tried various meshes but not even the best one seems to work well, with 66 non-orthogonality and 0.7 skewness.
I hope someone will give me some advice, thanks!