Regarding Experimental data comparison with real wind turb

BEM is not good for high speed wind turbine. Why still it is used in Industries?
Why cant complete RANS or LES be used to model a wind turbine than BEM?
In experiment Wind Turbine is rotated in particular RPM, what about the realwindturbine, does it rotate in same RPM. What is the normal operating wind speed and RPM of turbines?
NASA ames wind tunnel, blade is rotated at particular RPM via motor and Air is send at particular speed, but in reality wind turbine rotates by the speed of wind and RPM differs, How the CFD analysis can be extended for realtime wind turbines. Can anyone explain me?

Dear IjazFazil.SyedAhmedKabir,

BEM has its limitations, but has been sufficiently accurate for design purposes with appropriate corrections e.g. for airfoil data (including rotational augmentation), dynamics (dynamic wake and unsteady aero), hub/tip loss, and skewed flow. While CFD has been successfully applied to wind turbine analysis, it is not trivial to get correct solutions, and is too computationally expensive to run the thousands of load case simulations need for wind turbine design, especially considering the design iteration required.

Most wind turbines run with high tip-speed ratios (TSRs); TSR = 7 or 8 is common.

In a model-scale experiment, it is typically ensured that various dimensionless parameters are maintained in the scaling relationships, e.g., TSR and Reynolds number.

I hope that helps.

Best regards,