Rotating frame of reference simulation (icorio = 1) in Code_

[Gareth Gretton]

Hello,

I'm currently working on the simulation of a single blade of a horizontal axis tidal current turbine (think underwater wind turbine) in Code_Saturne.

The easiest way to do this (as far as I can see) is to model a single domain in a rotating frame of reference, such that the domain rotates with the turbine blade. This is specified by setting icorio = 1 in usini1.f90. Obviously this precludes modelling the tower of the turbine, or any sort of non-axisymmetric inflow condition, but I'm not too worried about these effects for now.

The domain around a single blade is in the form of a segment of a cylinder. As the turbine has 3 blades, this segment spans 120 degrees. The diameter of the domain is 2 turbine diameters or more, depending on how blocked we want the case to be.

Regarding boundary conditions, the turbine is positioned 5 (turbine) diameters downstream from the inlet boundary condition (on one axial face) and 40 diameters upstream from the oulet boundary condition (on the other axial face). The circumferential faces have a rotational periodic connection. I'm not sure what the best choice of boundary condition is for the radial face: I've tried symmetry, wall and inlet. Clearly the turbine blade has a no-slip wall boundary condition.

So far I've not been having much luck with these simulations - the results I get are just nonsense - and based on some things I've heard I'm wondering whether Code_Saturne is actually capable of simulating this sort of problem (without modification). As such, the main question here is: has anyone performed a similar sort of calculation, or can one of the developers say that this sort of problem can be simulated?

Best regards,

Gareth