[PedroSantos]

Hello guys,

For my master's thesis i need to validate a propeller with some data from another paper. Initially i did a simulation for a static test, just to see if the methodology worked. I have a rotating region with the propeller inside and i input the rotation ratio (RPMs), and then the static region and both are connected by interfaces. I followed a tutorial given by a university i did an erasmus in, and also followed some videos available online, whose methods were the same. You can see the mesh both regions in Mesh.jpg.

The static simulation worked well from what i understood, at least i had no problems. I set the timestep to match 1 degree of rotation. SST K-w turbulence model, ideal gas, segregated flow. The prism layers are built to achieve an y+ of around 1.
Static test.jpg

However i needed to validate thrust values for the propeller at 6000m of altitude, at mach 0.46, which at that altitude is about 145.9 m/s.

So i changed the Boundary values to the matching values at that altitude:
Reference Pressure around 40Kpa
Freestream speed of M 0.46 and Temp 250k
I also changed the initial conditions to match the BC.
The initial timesteps seem to be alright. But soon after the residuals skyrocket Residuals.jpg, and it appears this error Error.jpg. Some of the sims before diverging have these weird valuesDiveregence problems.jpg.


I spent more than a week doing parametric studies, changing the mesh, the time step, the initial conditions and nothing changes. I Would be really grateful for any suggestion, because i cant understand why this is happening...