Wake center of the curl model in FAST Farm

[MYMahfouz]

Dear all,

I want to know the wake center from the curl model output in FAST.Farm.

Can I use the output channel WkPosZTNDN for the height of the wake center?

I can see from the results that the height of the wake center is lower than the hub height of the turbine. I was expecting the wake center to be higher than the hub height because of the wake deflection.

The turbine I am simulating has a hub height of 135m, the results from WkPosZTNDN channel gives around 134.1m for a fixed bottom wind turbine and 134.5m for a floating turbine. These values are at a distance 4D behind the turbine.

If this is not the correct channel what channel can I use?

Thank you.

Best regards,
Youssef

[jjonkman]

Dear @MYMahfouz,

FAST.Farm outputs WkPosδTαDγ provide the (δ = X,Y,Z) coordinates of the center of a wake plane for the polar, curl, and Cartesian wake models. With the curled model, however, the wake center is not necessarily at the center of the wake plane due to its kidney-like shape. To calculate the actual center of a curled wake, it is better to post-process the wake center via a post-processing tool such as SAMWHICH: https://ewquon.github.io/waketracking/.

Best regards,

[MYMahfouz]

Dear @jjonkman,

Thank you for your reply.

I have tried to use SAMWICH as you suggested and I followed the example here.

It doesn't seem to be working as expected for all cases.

I have attached an example for the results I am getting at 1D behind the turbine.

Are there other examples or other methods for this calculation?

Thanks again for all the help.

Best regards

[jjonkman]

Dear @MYMahfouz,

Can you clarify what is not working?

That said, I've not used SAMWHICH myself, so, I'm not one that can provide much support. Perhaps others can comment or you can post your questions in the SAMWHICH repository.

Best regards,

[MYMahfouz]

Dear @jjonkman,

The result in the figure shows wake center at 112m height (below the hub center at 135m) and the contour doesn't cover the entire wake. This is why I am assuming I am doing something wrong or it isn't working as expected.

Are there other libraries/tools which you are aware of which I can try?

I will also post my question on the SAMWICH repo as you suggested.

Thanks for the help and the quick and useful reply.

Best regards

[jjonkman]

Dear @MYMahfouz,

SAMWHICH provides multiple ways of "fitting" the wake.

I'm not aware of other libraries/tools similar to SAMWHICH.

Best regards.