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OpenFAST / openfast

Main repository for the NREL-supported OpenFAST whole-turbine and FAST.Farm wind farm simulation codes.
http://openfast.readthedocs.io
Apache License 2.0
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Two questions about FAST #1878

Open Yongbyon opened 9 months ago

Yongbyon commented 9 months ago

Q1. There are a total of seven turbines here, each separated by a distance of 520 metres. The wake trend of the first four turbines is reasonable, but the wind speed of the last three is gradually rising, and even if I reduce the spacing between the last three turbines, the wind speed will still rising, how is that? The kind of wind I use is the steady wind. 总 平稳风 T1 T2 T3 T4 T5 T6 T7 Q2. The wind speed file generated by TurbSim, is the wind speed emanating from one point in all directions, or is it from the flow along the x-axis? Extremely grateful for your answer and look forward to your response!

jjonkman commented 9 months ago

Dear @Yongbyon,

Regarding (1), it is very difficult to interpret your results with only pictures of data columns. Can you share plots of the results to clarify your question. Regardless, it appears that you are running with steady, uniform inflow. Is that correct? Please note that FAST.Farm has not been calibrated for such a condition and may not produce accurate results, at least until the new wake-added turbulence model is added within https://github.com/OpenFAST/openfast/pull/1785.

Regarding (2), TurbSim generates a time-series of 3 components of the wind velocity (u.v,w) at each point in a 2D grid of points in the YZ plane (so called, "full-field" turbulence). Within OpenFAST and FAST.Farm, a 3D + time domain of inflow is generated by propagating the 2D planes along X axis based on the mean wind speed.

Best regards,

May0048 commented 9 months ago

Dear @jjonkman (1) When using turbulent wind in FAST.Farm, high-resolution and low-resolution grids need to be generated separately with TurbSim? (2) If the above is true, which InflowFiles should each of the two output files (.bts) be placed in? Low-resolution output file to InflowFile in .fstf file? High-resolution output file into the InflowFile in .fst file? Thanks,

jjonkman commented 9 months ago

Dear @May0048,

It looks like you asked similar questions in the following OpenFAST issue: https://github.com/OpenFAST/openfast/issues/1901; I've now responded there.

Best regards,