6DOF Savonius wind turbine problem?
 

Hi, Fluent Experts,

I am doing the Savonius wind turbine simulation. First, the simulation with sliding mesh was performed that agreed well with experimental data. Because, in sliding mesh setting, the rotational speed of the rotor is specified. Now, I am doing the dynamic mesh simulation with one DOF rotation setting to get real rotational speed. The simulation is 2D, the mass of turbine is not important in this simulation. I specify the moment of inertial, estimated by Solidworks, of 0.99N-m. First simulation was with velocity U = 7m/s and the second is U = 3m/s.
However, in both simulation, the averaged torque is very small that near zero. And the tip speed ratio reached to 1.8~1.9, as in figure below.
I wonder that, to get more real torque on the rotor, the Spring Preload and Spring Constant have to be specified? Without these parameter, the rotor typically freely rotate with high speed?
Thank you very much.

Any help, please!