Excesive torque in 2D VAWT simulation
 

I am doing a simulation to recreate the results of an experiment. However, the torque value doubles or triples the expected average torque value. Usually there is a residual torque of more or less 70 Nm and I get an average torque of 120 Nm (the expected average torque should be 51 Nm). I don't know what to do to correct it. I tried improving the mesh until y+<=1 was guaranteed. I verified that the bounday conditions were set correctly and verified that the simulation did converge. The method I use to simulate the background and the turbine is Oversetmesh. The Boundary conditions are: -Inlet: 1.62 m/s -w: 60 rpm (Cell zone turbine) -walls (moving walls). I am using SST k-w model