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Cp more than 0.59?
Hello, I'd like to ask a question. I conducted a turbine simulation, incorporating the wind field as an input, with a reference speed of 5 m/s and an ETMC value of 1 m/s (attached). The turbine I simulated has a radius of 2.7 m. After the simulation, the power coefficient graph indicates a value exceeding 0.593. Is this possible? Could you please explain?
regards
Setiawan
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Hello Setiawan,
the power coefficient (Cp) is primarily meaningful in a steady-state, uniform inflow, such as when evaluating the rotor Cp-TSR (Tip-Speed Ratio) curves during aerodynamic rotor design.
Evaluating the power coefficient requires a reference velocity; however, in a turbulent wind field, the local velocity fluctuates constantly. This variability can result in Cp values exceeding 0.59. A similar issue arises when the rotor operates in a steady boundary layer profile, where the velocity across the rotor is not uniform.
One note: On you attached image the windfield seems to be too small for the rotor diameter that you are simulating. I think that you should increase its size.
BR,
David
