Unable to Output Complete 2D Visualization Results for Steady Wind in FAST.Farm Simulation

[Steven647]

Hello Everyone，

I'm a Ph.D. student studying wind turbine aerodynamics, and I need some assistance with FAST.Farm.I am using FAST.Farm to simulate the wake of a wind turbine. The inflow wind is defined as steady wind in the InflowWind module, setting the . However, the wake visualization results cannot output content beyond the 2D(2 Diameter).

I am using the NREL 5MW wind turbine model with a rotor diameter of 126 m. In the InflowWind module, the parameter WindType is set to 1, and the wind speed is 11.4 m/s. In the main input file of FAST.Farm, the parameter Mod_Wake is set to 1, corresponding to the Polar Wake. In the VISUALIZATION section, NOutDisWindYZ is set to 9, with the corresponding OutDisWindX specifying 9 values. In the OUTPUT section, NOutDist is set to 8, with the corresponding OutDist defining 8 values at 1D intervals downstream of the turbine. However, in the visualization results of the wake, there is no wake data beyond a downstream distance of 2 rotor diameters from the turbine. The results are as follows:

OXY Plane

OXZ Plane

The main input file of FAST.Farm is as follows:
FAST.Farm.txt

I would appreciate any suggestions or insights on resolving this issue！

Best regards,
Steven Liu

[jjonkman]

Dear @Steven647

Your DT_Low is quite small for 11.4 m/s, so, the wake planes will be quite closely spaced and you would need many more wake planes to extend the wake further downstream. But it would be better to increase DT_Low to a more reasonable value.

I would suggest following the FAST.Farm modeling guidance when defining the spatial-temporal resolution: https://openfast.readthedocs.io/en/main/source/user/fast.farm/ModelGuidance.html.

Best regards,

[Steven647]

Dear @jjonkman

Thank you very much for your response and the suggestions provided. Following your advice, I have obtained the desired wake results. Once again, thank you!

Best regards,
Steven Liu