Issue of overestimated power output in single-turbine simulations of the NREL-5MW using the AMR-Wind and OpenFAST coupled framework.

[Zhiming-Cai]

Dear all,
When I used AMR-Wind + OpenFAST to calculate the power output of the NREL-5MW wind turbine, I encountered an issue.

First, let me briefly introduce some of my settings:

• AMR-Wind version: 3.4.0 (time step: 0.02s; the coarsest mesh resolution: 10 m; 1-level of adaptive mesh refinement based on passive scalar tagging)
• OpenFAST version: 4.0.2 (time step: 0.01s)
• Inflow condition: uniform, non-shear inflow with a wind speed of 8 m/s
• Simulation target: a single NREL-5MW wind turbine (blade mode DOFs, tower bending DOFs, and yaw DOF are all disabled)
• Coupling and flow field simulation method: actuator line model + Smagorinsky LES

However, after the simulation stabilized, I observed that the average power output of the turbine under 8 m/s inflow was over 2.6 MW, which clearly does not match the power coefficient curve for the NREL-5MW turbine.👇

I'm unsure what might be causing this discrepancy, and I would greatly appreciate any help or suggestions you can provide!
If more information is needed, please feel free to ask—I’ll be happy to provide additional details.

@jjonkman @NRELAdmin

[rthedin]

Note: cross-posted on AMR-Wind repo: Exawind/amr-wind#1553

[jjonkman]

This is more of an AMR-Wind question than an OpenFAST question, so, I assume someone from the AMR-Wind team will respond on that repository and I'll close this discussion here.