Pitch in Unsteady FINE/Turbo

For unsteady simulations, you must have the same periodicity on both sides of the R/S interface. If there are 12 vanes and 24 blades, you can use one vane and two blades.

Either simulate the full 360deg or find a common periodicity (as explained above).

Otherwise, if you have 12 vanes and 25 blades, you must approximate them to 24 blades and simulate them with one vane and two blades because there is no common periodicity in this case.

You may want to consider the Nonlinear Harmonic Method. You can find it in the Fine Turbo documentation under "Dedicated Turbomachinery Models" >> Harmonic Model.

In that way you can keep the number of guide vanes to match reality and to mesh only one passage of the guide vanes and one for the rotor blades, even if they have a different periodicity.

Hello,

I must be missing something. I already did my mesh with 20 GV blanes and a rotor with 40 blades, but the same error message appears. Where do I specify that I want 1 vane and 2 blades?

Navigate to AutoGrid software, right-click the rows, select the properties (the “Row Properties” interface will appear), and make the changes accordingly.

You can look for the "Number of Meshed Passages" in the Row Properties as also described in more detail in the Autogrid5 v18.1 documentation in the section "Project Setup" under chapter 3 Meshing Fundamentals.