Wind turbine simulation

[A1A235A5]

When I used this program to calculate the DTU wind turbine example, I found that the energy coefficient would exceed the Betz limit. which is 16/27. Later, I set the wind speed to 9m/s in the example of the NREL 5 MW wind turbine, and found that the calculated energy coefficient result was 0.6, which still exceeded the Betz limit. My calculation example and post-processing are completely based on the wind turbine in the example. I would like to know why the error occurs, whether it is in the calculation or post-processing. Looking forward to and thank you for your answer.