NREL Phase VI Wind Turbine
 

Hello guys,
I am performing simulations on the NREL wind turbine (radius:5m) in Fluent and I have generated mesh in ICEM with rotating mesh.
The problem is when I run simulation on 72 rpm it gets diverged and with 0.0005s time step. However I have managed to run the simulation with 10 rpm step of 0.005s and then I will gradually increase the rpm, that is the solution way I found out. I am running simulations with boundary layer because this is my first try. The simulation is running on transient SA turbulence model, Coupled Interface for moving mesh, inlet with 5m/s.

But I don't know how to monitor lift and drag coefficient of the turbine, the obtained values of the Lift coefficient is -20 and drag coefficient is 20 for 2.2 seconds.

Rotational axis is Y
Longitudinal axis is Z
Latitudinal axis is X
and I have set the 0 1 0 for drag coefficient and 0 -1 0 for lift coefficient. and I have selected both surface of the blade.

Image of reference value, residuals, lift and drag coefficient are attached.

Do anyone have idea how to monitor lift and drag coefficient. And what is the solution?

Thanks