Warning message : Coherent turbulence time step file

Discuss the effects of turbulence on wind turbines and its simulation.

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Warning message : Coherent turbulence time step file

Postby Atul.Patil » Sat Nov 29, 2014 10:35 am


I am running FAST and generating the .wnd file in turbsim for full field. i.e. velocity profile for grid area and tower height below the grid. Mean wind speed at 80m height (simplified Vestas 1.65 MW turbine model ) is 50 m/s. I am using time step 0.01.

The turbsim and fast runs normally and I do get .bts files (falg = true) . But I get the warning message : Coherent turbulence time step file can not be generated.

My very very basic understanding is that the coherent structures and interaction of fluid flow is boundary level turbulence problem.

I am not sure if the warning message could have any impact on the results. Any help is or suggestion would help. I appreciate your precious time.

Student , FSU

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Re: Warning message : Coherent turbulence time step file

Postby Bonnie.Jonkman » Tue Dec 02, 2014 10:25 am

The warning message you are receiving just indicates that you have specified some incompatible values in the TurbSim input file. The coherent structures files cannot be generated with IEC spectral models or with unstable boundary conditions (and a few other cases). See the TurbSim User's guide for more information. The easiest fix is just to set WrACT to False in the TurbSim input file.
Bonnie Jonkman

Envision Energy USA, 2016-
National Renewable Energy Laboratory, 2003-2016

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