WISDEM Validity

Wind & Water Structural Analysis
1

Hello,
I’m working in a small team that is starting to use WISDEM for some of our initial work. We have a couple of questions around the validity of the tool.

  1. If we simply swap out blade materials will the tool still be valid? Is there anything that needs to be updated long with the material properties?

  2. Is there a limit to the tool validity for the size of the blades, or the power output, or indeed for any of the inputs?

thanks!
Connor.

2

Hello Connor,

Thanks for your questions and interest in WISDEM. In general, WISDEM is a lower fidelity, steady state conceptual design tool, so it will never be as accurate as OpenFAST or a high-fidelity aero-structural code. Also, as will any optimization tool, it takes some practice and appreciation for a well posed problem. We have tried to guide users with the examples in that direction as much as possible.

For your questions:

  1. I might need a few more details to answer confidently, but if you are changing blade materials and layers in the yaml-file, and also enter in those material properties in the materials section of the yaml-file, then WISDEM is a great tool to explore that design concept. I would recommend re-optimizing the blade structural properties, mostly spar-cap thickness after any deviation from the baseline.

  2. We have done conceptual designs with WISDEM up to 25MW with extremely long blades. These are not designs that are ready for manufacturing, but they give you a good estimate of mass, cost, and performance. At that scale, some of the turbine components will be more realistic than others. The drivetrain, bearings, and other nacelle sub-components would be the most approximate. The cost models for components beyond the blades and towers would also come with sizeable error bars. However, there is no fundamental limit to going to higher ratings or rotor diameters in WISDEM. Just remember that just because a design can be modeled, doesn’t mean it is feasible to manufacture, transport, operate, etc.

Cheers,
Garrett

3

Hi Garrett,

Thanks for the information. That is very useful.

  1. So how do I re-optimise the blade structural properties, or does it do that automatically? I suppose I could see from the output files if the blade structure has changed.

  2. And to follow up on costing - is there some information on where labour and other costs come from in the model? At the moment I can see it’s USD/blade for example. It would be good to know how that cost is affected by the material or size of blade.

Many thanks,
Connor.

4

Hello @Garrett.Barter , just following up on this.

5

Hi Connor,

Sorry that I didn’t see your first reply. You can see an example blade structural optimization here.

For the background on the blade cost model, there is an NREL report that describes its approach and structure.

Cheers,
Garrett